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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-11 20:20:12 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-11 20:20:12 -0500
commit39cf275a1a18ba3c7eb9b986c5c9b35b57332798 (patch)
tree40b119ca9d2fbaf8128d3fa25f4c64669002b0c0 /kernel
parentad5d69899e52792671c1aa6c7360464c7edfe09c (diff)
parente5137b50a0640009fd63a3e65c14bc6e1be8796a (diff)
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar: "The main changes in this cycle are: - (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik van Riel, Peter Zijlstra et al. Yay! - optimize preemption counter handling: merge the NEED_RESCHED flag into the preempt_count variable, by Peter Zijlstra. - wait.h fixes and code reorganization from Peter Zijlstra - cfs_bandwidth fixes from Ben Segall - SMP load-balancer cleanups from Peter Zijstra - idle balancer improvements from Jason Low - other fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED stop_machine: Fix race between stop_two_cpus() and stop_cpus() sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus sched: Fix asymmetric scheduling for POWER7 sched: Move completion code from core.c to completion.c sched: Move wait code from core.c to wait.c sched: Move wait.c into kernel/sched/ sched/wait: Fix __wait_event_interruptible_lock_irq_timeout() sched: Avoid throttle_cfs_rq() racing with period_timer stopping sched: Guarantee new group-entities always have weight sched: Fix hrtimer_cancel()/rq->lock deadlock sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining sched: Fix race on toggling cfs_bandwidth_used sched: Remove extra put_online_cpus() inside sched_setaffinity() sched/rt: Fix task_tick_rt() comment sched/wait: Fix build breakage sched/wait: Introduce prepare_to_wait_event() sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too sched: Remove get_online_cpus() usage sched: Fix race in migrate_swap_stop() ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile2
-rw-r--r--kernel/bounds.c4
-rw-r--r--kernel/context_tracking.c2
-rw-r--r--kernel/cpu.c17
-rw-r--r--kernel/cpu/idle.c16
-rw-r--r--kernel/fork.c5
-rw-r--r--kernel/rcu/tree.c15
-rw-r--r--kernel/sched/Makefile1
-rw-r--r--kernel/sched/completion.c299
-rw-r--r--kernel/sched/core.c683
-rw-r--r--kernel/sched/debug.c68
-rw-r--r--kernel/sched/fair.c1397
-rw-r--r--kernel/sched/features.h19
-rw-r--r--kernel/sched/idle_task.c2
-rw-r--r--kernel/sched/rt.c22
-rw-r--r--kernel/sched/sched.h54
-rw-r--r--kernel/sched/stats.h46
-rw-r--r--kernel/sched/stop_task.c2
-rw-r--r--kernel/sched/wait.c (renamed from kernel/wait.c)127
-rw-r--r--kernel/softirq.c16
-rw-r--r--kernel/stop_machine.c303
-rw-r--r--kernel/sysctl.c21
-rw-r--r--kernel/timer.c8
-rw-r--r--kernel/trace/trace.c3
-rw-r--r--kernel/trace/trace.h1
-rw-r--r--kernel/trace/trace_output.c19
26 files changed, 2325 insertions, 827 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index f99d908b5550..a4d1aa8da9bc 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -7,7 +7,7 @@ obj-y = fork.o exec_domain.o panic.o \
7 sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \ 7 sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
8 signal.o sys.o kmod.o workqueue.o pid.o task_work.o \ 8 signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
9 extable.o params.o posix-timers.o \ 9 extable.o params.o posix-timers.o \
10 kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \ 10 kthread.o sys_ni.o posix-cpu-timers.o mutex.o \
11 hrtimer.o rwsem.o nsproxy.o semaphore.o \ 11 hrtimer.o rwsem.o nsproxy.o semaphore.o \
12 notifier.o ksysfs.o cred.o reboot.o \ 12 notifier.o ksysfs.o cred.o reboot.o \
13 async.o range.o groups.o lglock.o smpboot.o 13 async.o range.o groups.o lglock.o smpboot.o
diff --git a/kernel/bounds.c b/kernel/bounds.c
index 0c9b862292b2..e8ca97b5c386 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -10,6 +10,7 @@
10#include <linux/mmzone.h> 10#include <linux/mmzone.h>
11#include <linux/kbuild.h> 11#include <linux/kbuild.h>
12#include <linux/page_cgroup.h> 12#include <linux/page_cgroup.h>
13#include <linux/log2.h>
13 14
14void foo(void) 15void foo(void)
15{ 16{
@@ -17,5 +18,8 @@ void foo(void)
17 DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS); 18 DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
18 DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES); 19 DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
19 DEFINE(NR_PCG_FLAGS, __NR_PCG_FLAGS); 20 DEFINE(NR_PCG_FLAGS, __NR_PCG_FLAGS);
21#ifdef CONFIG_SMP
22 DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
23#endif
20 /* End of constants */ 24 /* End of constants */
21} 25}
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 859c8dfd78a1..e5f3917aa05b 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -120,7 +120,7 @@ void context_tracking_user_enter(void)
120 * instead of preempt_schedule() to exit user context if needed before 120 * instead of preempt_schedule() to exit user context if needed before
121 * calling the scheduler. 121 * calling the scheduler.
122 */ 122 */
123void __sched notrace preempt_schedule_context(void) 123asmlinkage void __sched notrace preempt_schedule_context(void)
124{ 124{
125 enum ctx_state prev_ctx; 125 enum ctx_state prev_ctx;
126 126
diff --git a/kernel/cpu.c b/kernel/cpu.c
index d7f07a2da5a6..63aa50d7ce1e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -308,6 +308,23 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
308 } 308 }
309 smpboot_park_threads(cpu); 309 smpboot_park_threads(cpu);
310 310
311 /*
312 * By now we've cleared cpu_active_mask, wait for all preempt-disabled
313 * and RCU users of this state to go away such that all new such users
314 * will observe it.
315 *
316 * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
317 * not imply sync_sched(), so explicitly call both.
318 */
319#ifdef CONFIG_PREEMPT
320 synchronize_sched();
321#endif
322 synchronize_rcu();
323
324 /*
325 * So now all preempt/rcu users must observe !cpu_active().
326 */
327
311 err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); 328 err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
312 if (err) { 329 if (err) {
313 /* CPU didn't die: tell everyone. Can't complain. */ 330 /* CPU didn't die: tell everyone. Can't complain. */
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
index e695c0a0bcb5..988573a9a387 100644
--- a/kernel/cpu/idle.c
+++ b/kernel/cpu/idle.c
@@ -44,7 +44,7 @@ static inline int cpu_idle_poll(void)
44 rcu_idle_enter(); 44 rcu_idle_enter();
45 trace_cpu_idle_rcuidle(0, smp_processor_id()); 45 trace_cpu_idle_rcuidle(0, smp_processor_id());
46 local_irq_enable(); 46 local_irq_enable();
47 while (!need_resched()) 47 while (!tif_need_resched())
48 cpu_relax(); 48 cpu_relax();
49 trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); 49 trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
50 rcu_idle_exit(); 50 rcu_idle_exit();
@@ -92,8 +92,7 @@ static void cpu_idle_loop(void)
92 if (cpu_idle_force_poll || tick_check_broadcast_expired()) { 92 if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
93 cpu_idle_poll(); 93 cpu_idle_poll();
94 } else { 94 } else {
95 current_clr_polling(); 95 if (!current_clr_polling_and_test()) {
96 if (!need_resched()) {
97 stop_critical_timings(); 96 stop_critical_timings();
98 rcu_idle_enter(); 97 rcu_idle_enter();
99 arch_cpu_idle(); 98 arch_cpu_idle();
@@ -103,9 +102,16 @@ static void cpu_idle_loop(void)
103 } else { 102 } else {
104 local_irq_enable(); 103 local_irq_enable();
105 } 104 }
106 current_set_polling(); 105 __current_set_polling();
107 } 106 }
108 arch_cpu_idle_exit(); 107 arch_cpu_idle_exit();
108 /*
109 * We need to test and propagate the TIF_NEED_RESCHED
110 * bit here because we might not have send the
111 * reschedule IPI to idle tasks.
112 */
113 if (tif_need_resched())
114 set_preempt_need_resched();
109 } 115 }
110 tick_nohz_idle_exit(); 116 tick_nohz_idle_exit();
111 schedule_preempt_disabled(); 117 schedule_preempt_disabled();
@@ -129,7 +135,7 @@ void cpu_startup_entry(enum cpuhp_state state)
129 */ 135 */
130 boot_init_stack_canary(); 136 boot_init_stack_canary();
131#endif 137#endif
132 current_set_polling(); 138 __current_set_polling();
133 arch_cpu_idle_prepare(); 139 arch_cpu_idle_prepare();
134 cpu_idle_loop(); 140 cpu_idle_loop();
135} 141}
diff --git a/kernel/fork.c b/kernel/fork.c
index 8531609b6a82..f6d11fc67f72 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -817,9 +817,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
817#ifdef CONFIG_TRANSPARENT_HUGEPAGE 817#ifdef CONFIG_TRANSPARENT_HUGEPAGE
818 mm->pmd_huge_pte = NULL; 818 mm->pmd_huge_pte = NULL;
819#endif 819#endif
820#ifdef CONFIG_NUMA_BALANCING
821 mm->first_nid = NUMA_PTE_SCAN_INIT;
822#endif
823 if (!mm_init(mm, tsk)) 820 if (!mm_init(mm, tsk))
824 goto fail_nomem; 821 goto fail_nomem;
825 822
@@ -1313,7 +1310,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
1313#endif 1310#endif
1314 1311
1315 /* Perform scheduler related setup. Assign this task to a CPU. */ 1312 /* Perform scheduler related setup. Assign this task to a CPU. */
1316 sched_fork(p); 1313 sched_fork(clone_flags, p);
1317 1314
1318 retval = perf_event_init_task(p); 1315 retval = perf_event_init_task(p);
1319 if (retval) 1316 if (retval)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8a2c81e86dda..4c06ddfea7cd 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -916,6 +916,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
916 force_quiescent_state(rsp); /* Kick them all. */ 916 force_quiescent_state(rsp); /* Kick them all. */
917} 917}
918 918
919/*
920 * This function really isn't for public consumption, but RCU is special in
921 * that context switches can allow the state machine to make progress.
922 */
923extern void resched_cpu(int cpu);
924
919static void print_cpu_stall(struct rcu_state *rsp) 925static void print_cpu_stall(struct rcu_state *rsp)
920{ 926{
921 int cpu; 927 int cpu;
@@ -945,7 +951,14 @@ static void print_cpu_stall(struct rcu_state *rsp)
945 3 * rcu_jiffies_till_stall_check() + 3; 951 3 * rcu_jiffies_till_stall_check() + 3;
946 raw_spin_unlock_irqrestore(&rnp->lock, flags); 952 raw_spin_unlock_irqrestore(&rnp->lock, flags);
947 953
948 set_need_resched(); /* kick ourselves to get things going. */ 954 /*
955 * Attempt to revive the RCU machinery by forcing a context switch.
956 *
957 * A context switch would normally allow the RCU state machine to make
958 * progress and it could be we're stuck in kernel space without context
959 * switches for an entirely unreasonable amount of time.
960 */
961 resched_cpu(smp_processor_id());
949} 962}
950 963
951static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) 964static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 54adcf35f495..7b621409cf15 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -12,6 +12,7 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
12endif 12endif
13 13
14obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o 14obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
15obj-y += wait.o completion.o
15obj-$(CONFIG_SMP) += cpupri.o 16obj-$(CONFIG_SMP) += cpupri.o
16obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o 17obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
17obj-$(CONFIG_SCHEDSTATS) += stats.o 18obj-$(CONFIG_SCHEDSTATS) += stats.o
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
new file mode 100644
index 000000000000..a63f4dc27909
--- /dev/null
+++ b/kernel/sched/completion.c
@@ -0,0 +1,299 @@
1/*
2 * Generic wait-for-completion handler;
3 *
4 * It differs from semaphores in that their default case is the opposite,
5 * wait_for_completion default blocks whereas semaphore default non-block. The
6 * interface also makes it easy to 'complete' multiple waiting threads,
7 * something which isn't entirely natural for semaphores.
8 *
9 * But more importantly, the primitive documents the usage. Semaphores would
10 * typically be used for exclusion which gives rise to priority inversion.
11 * Waiting for completion is a typically sync point, but not an exclusion point.
12 */
13
14#include <linux/sched.h>
15#include <linux/completion.h>
16
17/**
18 * complete: - signals a single thread waiting on this completion
19 * @x: holds the state of this particular completion
20 *
21 * This will wake up a single thread waiting on this completion. Threads will be
22 * awakened in the same order in which they were queued.
23 *
24 * See also complete_all(), wait_for_completion() and related routines.
25 *
26 * It may be assumed that this function implies a write memory barrier before
27 * changing the task state if and only if any tasks are woken up.
28 */
29void complete(struct completion *x)
30{
31 unsigned long flags;
32
33 spin_lock_irqsave(&x->wait.lock, flags);
34 x->done++;
35 __wake_up_locked(&x->wait, TASK_NORMAL, 1);
36 spin_unlock_irqrestore(&x->wait.lock, flags);
37}
38EXPORT_SYMBOL(complete);
39
40/**
41 * complete_all: - signals all threads waiting on this completion
42 * @x: holds the state of this particular completion
43 *
44 * This will wake up all threads waiting on this particular completion event.
45 *
46 * It may be assumed that this function implies a write memory barrier before
47 * changing the task state if and only if any tasks are woken up.
48 */
49void complete_all(struct completion *x)
50{
51 unsigned long flags;
52
53 spin_lock_irqsave(&x->wait.lock, flags);
54 x->done += UINT_MAX/2;
55 __wake_up_locked(&x->wait, TASK_NORMAL, 0);
56 spin_unlock_irqrestore(&x->wait.lock, flags);
57}
58EXPORT_SYMBOL(complete_all);
59
60static inline long __sched
61do_wait_for_common(struct completion *x,
62 long (*action)(long), long timeout, int state)
63{
64 if (!x->done) {
65 DECLARE_WAITQUEUE(wait, current);
66
67 __add_wait_queue_tail_exclusive(&x->wait, &wait);
68 do {
69 if (signal_pending_state(state, current)) {
70 timeout = -ERESTARTSYS;
71 break;
72 }
73 __set_current_state(state);
74 spin_unlock_irq(&x->wait.lock);
75 timeout = action(timeout);
76 spin_lock_irq(&x->wait.lock);
77 } while (!x->done && timeout);
78 __remove_wait_queue(&x->wait, &wait);
79 if (!x->done)
80 return timeout;
81 }
82 x->done--;
83 return timeout ?: 1;
84}
85
86static inline long __sched
87__wait_for_common(struct completion *x,
88 long (*action)(long), long timeout, int state)
89{
90 might_sleep();
91
92 spin_lock_irq(&x->wait.lock);
93 timeout = do_wait_for_common(x, action, timeout, state);
94 spin_unlock_irq(&x->wait.lock);
95 return timeout;
96}
97
98static long __sched
99wait_for_common(struct completion *x, long timeout, int state)
100{
101 return __wait_for_common(x, schedule_timeout, timeout, state);
102}
103
104static long __sched
105wait_for_common_io(struct completion *x, long timeout, int state)
106{
107 return __wait_for_common(x, io_schedule_timeout, timeout, state);
108}
109
110/**
111 * wait_for_completion: - waits for completion of a task
112 * @x: holds the state of this particular completion
113 *
114 * This waits to be signaled for completion of a specific task. It is NOT
115 * interruptible and there is no timeout.
116 *
117 * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
118 * and interrupt capability. Also see complete().
119 */
120void __sched wait_for_completion(struct completion *x)
121{
122 wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
123}
124EXPORT_SYMBOL(wait_for_completion);
125
126/**
127 * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
128 * @x: holds the state of this particular completion
129 * @timeout: timeout value in jiffies
130 *
131 * This waits for either a completion of a specific task to be signaled or for a
132 * specified timeout to expire. The timeout is in jiffies. It is not
133 * interruptible.
134 *
135 * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
136 * till timeout) if completed.
137 */
138unsigned long __sched
139wait_for_completion_timeout(struct completion *x, unsigned long timeout)
140{
141 return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
142}
143EXPORT_SYMBOL(wait_for_completion_timeout);
144
145/**
146 * wait_for_completion_io: - waits for completion of a task
147 * @x: holds the state of this particular completion
148 *
149 * This waits to be signaled for completion of a specific task. It is NOT
150 * interruptible and there is no timeout. The caller is accounted as waiting
151 * for IO.
152 */
153void __sched wait_for_completion_io(struct completion *x)
154{
155 wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
156}
157EXPORT_SYMBOL(wait_for_completion_io);
158
159/**
160 * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
161 * @x: holds the state of this particular completion
162 * @timeout: timeout value in jiffies
163 *
164 * This waits for either a completion of a specific task to be signaled or for a
165 * specified timeout to expire. The timeout is in jiffies. It is not
166 * interruptible. The caller is accounted as waiting for IO.
167 *
168 * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
169 * till timeout) if completed.
170 */
171unsigned long __sched
172wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
173{
174 return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
175}
176EXPORT_SYMBOL(wait_for_completion_io_timeout);
177
178/**
179 * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
180 * @x: holds the state of this particular completion
181 *
182 * This waits for completion of a specific task to be signaled. It is
183 * interruptible.
184 *
185 * Return: -ERESTARTSYS if interrupted, 0 if completed.
186 */
187int __sched wait_for_completion_interruptible(struct completion *x)
188{
189 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
190 if (t == -ERESTARTSYS)
191 return t;
192 return 0;
193}
194EXPORT_SYMBOL(wait_for_completion_interruptible);
195
196/**
197 * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
198 * @x: holds the state of this particular completion
199 * @timeout: timeout value in jiffies
200 *
201 * This waits for either a completion of a specific task to be signaled or for a
202 * specified timeout to expire. It is interruptible. The timeout is in jiffies.
203 *
204 * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
205 * or number of jiffies left till timeout) if completed.
206 */
207long __sched
208wait_for_completion_interruptible_timeout(struct completion *x,
209 unsigned long timeout)
210{
211 return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
212}
213EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
214
215/**
216 * wait_for_completion_killable: - waits for completion of a task (killable)
217 * @x: holds the state of this particular completion
218 *
219 * This waits to be signaled for completion of a specific task. It can be
220 * interrupted by a kill signal.
221 *
222 * Return: -ERESTARTSYS if interrupted, 0 if completed.
223 */
224int __sched wait_for_completion_killable(struct completion *x)
225{
226 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
227 if (t == -ERESTARTSYS)
228 return t;
229 return 0;
230}
231EXPORT_SYMBOL(wait_for_completion_killable);
232
233/**
234 * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
235 * @x: holds the state of this particular completion
236 * @timeout: timeout value in jiffies
237 *
238 * This waits for either a completion of a specific task to be
239 * signaled or for a specified timeout to expire. It can be
240 * interrupted by a kill signal. The timeout is in jiffies.
241 *
242 * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
243 * or number of jiffies left till timeout) if completed.
244 */
245long __sched
246wait_for_completion_killable_timeout(struct completion *x,
247 unsigned long timeout)
248{
249 return wait_for_common(x, timeout, TASK_KILLABLE);
250}
251EXPORT_SYMBOL(wait_for_completion_killable_timeout);
252
253/**
254 * try_wait_for_completion - try to decrement a completion without blocking
255 * @x: completion structure
256 *
257 * Return: 0 if a decrement cannot be done without blocking
258 * 1 if a decrement succeeded.
259 *
260 * If a completion is being used as a counting completion,
261 * attempt to decrement the counter without blocking. This
262 * enables us to avoid waiting if the resource the completion
263 * is protecting is not available.
264 */
265bool try_wait_for_completion(struct completion *x)
266{
267 unsigned long flags;
268 int ret = 1;
269
270 spin_lock_irqsave(&x->wait.lock, flags);
271 if (!x->done)
272 ret = 0;
273 else
274 x->done--;
275 spin_unlock_irqrestore(&x->wait.lock, flags);
276 return ret;
277}
278EXPORT_SYMBOL(try_wait_for_completion);
279
280/**
281 * completion_done - Test to see if a completion has any waiters
282 * @x: completion structure
283 *
284 * Return: 0 if there are waiters (wait_for_completion() in progress)
285 * 1 if there are no waiters.
286 *
287 */
288bool completion_done(struct completion *x)
289{
290 unsigned long flags;
291 int ret = 1;
292
293 spin_lock_irqsave(&x->wait.lock, flags);
294 if (!x->done)
295 ret = 0;
296 spin_unlock_irqrestore(&x->wait.lock, flags);
297 return ret;
298}
299EXPORT_SYMBOL(completion_done);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5ac63c9a995a..1deccd78be98 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -513,12 +513,11 @@ static inline void init_hrtick(void)
513 * might also involve a cross-CPU call to trigger the scheduler on 513 * might also involve a cross-CPU call to trigger the scheduler on
514 * the target CPU. 514 * the target CPU.
515 */ 515 */
516#ifdef CONFIG_SMP
517void resched_task(struct task_struct *p) 516void resched_task(struct task_struct *p)
518{ 517{
519 int cpu; 518 int cpu;
520 519
521 assert_raw_spin_locked(&task_rq(p)->lock); 520 lockdep_assert_held(&task_rq(p)->lock);
522 521
523 if (test_tsk_need_resched(p)) 522 if (test_tsk_need_resched(p))
524 return; 523 return;
@@ -526,8 +525,10 @@ void resched_task(struct task_struct *p)
526 set_tsk_need_resched(p); 525 set_tsk_need_resched(p);
527 526
528 cpu = task_cpu(p); 527 cpu = task_cpu(p);
529 if (cpu == smp_processor_id()) 528 if (cpu == smp_processor_id()) {
529 set_preempt_need_resched();
530 return; 530 return;
531 }
531 532
532 /* NEED_RESCHED must be visible before we test polling */ 533 /* NEED_RESCHED must be visible before we test polling */
533 smp_mb(); 534 smp_mb();
@@ -546,6 +547,7 @@ void resched_cpu(int cpu)
546 raw_spin_unlock_irqrestore(&rq->lock, flags); 547 raw_spin_unlock_irqrestore(&rq->lock, flags);
547} 548}
548 549
550#ifdef CONFIG_SMP
549#ifdef CONFIG_NO_HZ_COMMON 551#ifdef CONFIG_NO_HZ_COMMON
550/* 552/*
551 * In the semi idle case, use the nearest busy cpu for migrating timers 553 * In the semi idle case, use the nearest busy cpu for migrating timers
@@ -693,12 +695,6 @@ void sched_avg_update(struct rq *rq)
693 } 695 }
694} 696}
695 697
696#else /* !CONFIG_SMP */
697void resched_task(struct task_struct *p)
698{
699 assert_raw_spin_locked(&task_rq(p)->lock);
700 set_tsk_need_resched(p);
701}
702#endif /* CONFIG_SMP */ 698#endif /* CONFIG_SMP */
703 699
704#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ 700#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
@@ -767,14 +763,14 @@ static void set_load_weight(struct task_struct *p)
767static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) 763static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
768{ 764{
769 update_rq_clock(rq); 765 update_rq_clock(rq);
770 sched_info_queued(p); 766 sched_info_queued(rq, p);
771 p->sched_class->enqueue_task(rq, p, flags); 767 p->sched_class->enqueue_task(rq, p, flags);
772} 768}
773 769
774static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) 770static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
775{ 771{
776 update_rq_clock(rq); 772 update_rq_clock(rq);
777 sched_info_dequeued(p); 773 sched_info_dequeued(rq, p);
778 p->sched_class->dequeue_task(rq, p, flags); 774 p->sched_class->dequeue_task(rq, p, flags);
779} 775}
780 776
@@ -987,7 +983,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
987 * ttwu() will sort out the placement. 983 * ttwu() will sort out the placement.
988 */ 984 */
989 WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && 985 WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
990 !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); 986 !(task_preempt_count(p) & PREEMPT_ACTIVE));
991 987
992#ifdef CONFIG_LOCKDEP 988#ifdef CONFIG_LOCKDEP
993 /* 989 /*
@@ -1017,6 +1013,107 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
1017 __set_task_cpu(p, new_cpu); 1013 __set_task_cpu(p, new_cpu);
1018} 1014}
1019 1015
1016static void __migrate_swap_task(struct task_struct *p, int cpu)
1017{
1018 if (p->on_rq) {
1019 struct rq *src_rq, *dst_rq;
1020
1021 src_rq = task_rq(p);
1022 dst_rq = cpu_rq(cpu);
1023
1024 deactivate_task(src_rq, p, 0);
1025 set_task_cpu(p, cpu);
1026 activate_task(dst_rq, p, 0);
1027 check_preempt_curr(dst_rq, p, 0);
1028 } else {
1029 /*
1030 * Task isn't running anymore; make it appear like we migrated
1031 * it before it went to sleep. This means on wakeup we make the
1032 * previous cpu our targer instead of where it really is.
1033 */
1034 p->wake_cpu = cpu;
1035 }
1036}
1037
1038struct migration_swap_arg {
1039 struct task_struct *src_task, *dst_task;
1040 int src_cpu, dst_cpu;
1041};
1042
1043static int migrate_swap_stop(void *data)
1044{
1045 struct migration_swap_arg *arg = data;
1046 struct rq *src_rq, *dst_rq;
1047 int ret = -EAGAIN;
1048
1049 src_rq = cpu_rq(arg->src_cpu);
1050 dst_rq = cpu_rq(arg->dst_cpu);
1051
1052 double_raw_lock(&arg->src_task->pi_lock,
1053 &arg->dst_task->pi_lock);
1054 double_rq_lock(src_rq, dst_rq);
1055 if (task_cpu(arg->dst_task) != arg->dst_cpu)
1056 goto unlock;
1057
1058 if (task_cpu(arg->src_task) != arg->src_cpu)
1059 goto unlock;
1060
1061 if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task)))
1062 goto unlock;
1063
1064 if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task)))
1065 goto unlock;
1066
1067 __migrate_swap_task(arg->src_task, arg->dst_cpu);
1068 __migrate_swap_task(arg->dst_task, arg->src_cpu);
1069
1070 ret = 0;
1071
1072unlock:
1073 double_rq_unlock(src_rq, dst_rq);
1074 raw_spin_unlock(&arg->dst_task->pi_lock);
1075 raw_spin_unlock(&arg->src_task->pi_lock);
1076
1077 return ret;
1078}
1079
1080/*
1081 * Cross migrate two tasks
1082 */
1083int migrate_swap(struct task_struct *cur, struct task_struct *p)
1084{
1085 struct migration_swap_arg arg;
1086 int ret = -EINVAL;
1087
1088 arg = (struct migration_swap_arg){
1089 .src_task = cur,
1090 .src_cpu = task_cpu(cur),
1091 .dst_task = p,
1092 .dst_cpu = task_cpu(p),
1093 };
1094
1095 if (arg.src_cpu == arg.dst_cpu)
1096 goto out;
1097
1098 /*
1099 * These three tests are all lockless; this is OK since all of them
1100 * will be re-checked with proper locks held further down the line.
1101 */
1102 if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu))
1103 goto out;
1104
1105 if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task)))
1106 goto out;
1107
1108 if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task)))
1109 goto out;
1110
1111 ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg);
1112
1113out:
1114 return ret;
1115}
1116
1020struct migration_arg { 1117struct migration_arg {
1021 struct task_struct *task; 1118 struct task_struct *task;
1022 int dest_cpu; 1119 int dest_cpu;
@@ -1236,9 +1333,9 @@ out:
1236 * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. 1333 * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
1237 */ 1334 */
1238static inline 1335static inline
1239int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) 1336int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
1240{ 1337{
1241 int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); 1338 cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);
1242 1339
1243 /* 1340 /*
1244 * In order not to call set_task_cpu() on a blocking task we need 1341 * In order not to call set_task_cpu() on a blocking task we need
@@ -1330,12 +1427,13 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
1330 1427
1331 if (rq->idle_stamp) { 1428 if (rq->idle_stamp) {
1332 u64 delta = rq_clock(rq) - rq->idle_stamp; 1429 u64 delta = rq_clock(rq) - rq->idle_stamp;
1333 u64 max = 2*sysctl_sched_migration_cost; 1430 u64 max = 2*rq->max_idle_balance_cost;
1431
1432 update_avg(&rq->avg_idle, delta);
1334 1433
1335 if (delta > max) 1434 if (rq->avg_idle > max)
1336 rq->avg_idle = max; 1435 rq->avg_idle = max;
1337 else 1436
1338 update_avg(&rq->avg_idle, delta);
1339 rq->idle_stamp = 0; 1437 rq->idle_stamp = 0;
1340 } 1438 }
1341#endif 1439#endif
@@ -1396,6 +1494,14 @@ static void sched_ttwu_pending(void)
1396 1494
1397void scheduler_ipi(void) 1495void scheduler_ipi(void)
1398{ 1496{
1497 /*
1498 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1499 * TIF_NEED_RESCHED remotely (for the first time) will also send
1500 * this IPI.
1501 */
1502 if (tif_need_resched())
1503 set_preempt_need_resched();
1504
1399 if (llist_empty(&this_rq()->wake_list) 1505 if (llist_empty(&this_rq()->wake_list)
1400 && !tick_nohz_full_cpu(smp_processor_id()) 1506 && !tick_nohz_full_cpu(smp_processor_id())
1401 && !got_nohz_idle_kick()) 1507 && !got_nohz_idle_kick())
@@ -1513,7 +1619,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
1513 if (p->sched_class->task_waking) 1619 if (p->sched_class->task_waking)
1514 p->sched_class->task_waking(p); 1620 p->sched_class->task_waking(p);
1515 1621
1516 cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); 1622 cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
1517 if (task_cpu(p) != cpu) { 1623 if (task_cpu(p) != cpu) {
1518 wake_flags |= WF_MIGRATED; 1624 wake_flags |= WF_MIGRATED;
1519 set_task_cpu(p, cpu); 1625 set_task_cpu(p, cpu);
@@ -1595,7 +1701,7 @@ int wake_up_state(struct task_struct *p, unsigned int state)
1595 * 1701 *
1596 * __sched_fork() is basic setup used by init_idle() too: 1702 * __sched_fork() is basic setup used by init_idle() too:
1597 */ 1703 */
1598static void __sched_fork(struct task_struct *p) 1704static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
1599{ 1705{
1600 p->on_rq = 0; 1706 p->on_rq = 0;
1601 1707
@@ -1619,16 +1725,24 @@ static void __sched_fork(struct task_struct *p)
1619 1725
1620#ifdef CONFIG_NUMA_BALANCING 1726#ifdef CONFIG_NUMA_BALANCING
1621 if (p->mm && atomic_read(&p->mm->mm_users) == 1) { 1727 if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
1622 p->mm->numa_next_scan = jiffies; 1728 p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
1623 p->mm->numa_next_reset = jiffies;
1624 p->mm->numa_scan_seq = 0; 1729 p->mm->numa_scan_seq = 0;
1625 } 1730 }
1626 1731
1732 if (clone_flags & CLONE_VM)
1733 p->numa_preferred_nid = current->numa_preferred_nid;
1734 else
1735 p->numa_preferred_nid = -1;
1736
1627 p->node_stamp = 0ULL; 1737 p->node_stamp = 0ULL;
1628 p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; 1738 p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
1629 p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0;
1630 p->numa_scan_period = sysctl_numa_balancing_scan_delay; 1739 p->numa_scan_period = sysctl_numa_balancing_scan_delay;
1631 p->numa_work.next = &p->numa_work; 1740 p->numa_work.next = &p->numa_work;
1741 p->numa_faults = NULL;
1742 p->numa_faults_buffer = NULL;
1743
1744 INIT_LIST_HEAD(&p->numa_entry);
1745 p->numa_group = NULL;
1632#endif /* CONFIG_NUMA_BALANCING */ 1746#endif /* CONFIG_NUMA_BALANCING */
1633} 1747}
1634 1748
@@ -1654,12 +1768,12 @@ void set_numabalancing_state(bool enabled)
1654/* 1768/*
1655 * fork()/clone()-time setup: 1769 * fork()/clone()-time setup:
1656 */ 1770 */
1657void sched_fork(struct task_struct *p) 1771void sched_fork(unsigned long clone_flags, struct task_struct *p)
1658{ 1772{
1659 unsigned long flags; 1773 unsigned long flags;
1660 int cpu = get_cpu(); 1774 int cpu = get_cpu();
1661 1775
1662 __sched_fork(p); 1776 __sched_fork(clone_flags, p);
1663 /* 1777 /*
1664 * We mark the process as running here. This guarantees that 1778 * We mark the process as running here. This guarantees that
1665 * nobody will actually run it, and a signal or other external 1779 * nobody will actually run it, and a signal or other external
@@ -1717,10 +1831,7 @@ void sched_fork(struct task_struct *p)
1717#if defined(CONFIG_SMP) 1831#if defined(CONFIG_SMP)
1718 p->on_cpu = 0; 1832 p->on_cpu = 0;
1719#endif 1833#endif
1720#ifdef CONFIG_PREEMPT_COUNT 1834 init_task_preempt_count(p);
1721 /* Want to start with kernel preemption disabled. */
1722 task_thread_info(p)->preempt_count = 1;
1723#endif
1724#ifdef CONFIG_SMP 1835#ifdef CONFIG_SMP
1725 plist_node_init(&p->pushable_tasks, MAX_PRIO); 1836 plist_node_init(&p->pushable_tasks, MAX_PRIO);
1726#endif 1837#endif
@@ -1747,7 +1858,7 @@ void wake_up_new_task(struct task_struct *p)
1747 * - cpus_allowed can change in the fork path 1858 * - cpus_allowed can change in the fork path
1748 * - any previously selected cpu might disappear through hotplug 1859 * - any previously selected cpu might disappear through hotplug
1749 */ 1860 */
1750 set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); 1861 set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0));
1751#endif 1862#endif
1752 1863
1753 /* Initialize new task's runnable average */ 1864 /* Initialize new task's runnable average */
@@ -1838,7 +1949,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
1838 struct task_struct *next) 1949 struct task_struct *next)
1839{ 1950{
1840 trace_sched_switch(prev, next); 1951 trace_sched_switch(prev, next);
1841 sched_info_switch(prev, next); 1952 sched_info_switch(rq, prev, next);
1842 perf_event_task_sched_out(prev, next); 1953 perf_event_task_sched_out(prev, next);
1843 fire_sched_out_preempt_notifiers(prev, next); 1954 fire_sched_out_preempt_notifiers(prev, next);
1844 prepare_lock_switch(rq, next); 1955 prepare_lock_switch(rq, next);
@@ -1890,6 +2001,8 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
1890 if (mm) 2001 if (mm)
1891 mmdrop(mm); 2002 mmdrop(mm);
1892 if (unlikely(prev_state == TASK_DEAD)) { 2003 if (unlikely(prev_state == TASK_DEAD)) {
2004 task_numa_free(prev);
2005
1893 /* 2006 /*
1894 * Remove function-return probe instances associated with this 2007 * Remove function-return probe instances associated with this
1895 * task and put them back on the free list. 2008 * task and put them back on the free list.
@@ -2073,7 +2186,7 @@ void sched_exec(void)
2073 int dest_cpu; 2186 int dest_cpu;
2074 2187
2075 raw_spin_lock_irqsave(&p->pi_lock, flags); 2188 raw_spin_lock_irqsave(&p->pi_lock, flags);
2076 dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); 2189 dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0);
2077 if (dest_cpu == smp_processor_id()) 2190 if (dest_cpu == smp_processor_id())
2078 goto unlock; 2191 goto unlock;
2079 2192
@@ -2215,7 +2328,7 @@ notrace unsigned long get_parent_ip(unsigned long addr)
2215#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ 2328#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
2216 defined(CONFIG_PREEMPT_TRACER)) 2329 defined(CONFIG_PREEMPT_TRACER))
2217 2330
2218void __kprobes add_preempt_count(int val) 2331void __kprobes preempt_count_add(int val)
2219{ 2332{
2220#ifdef CONFIG_DEBUG_PREEMPT 2333#ifdef CONFIG_DEBUG_PREEMPT
2221 /* 2334 /*
@@ -2224,7 +2337,7 @@ void __kprobes add_preempt_count(int val)
2224 if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) 2337 if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
2225 return; 2338 return;
2226#endif 2339#endif
2227 preempt_count() += val; 2340 __preempt_count_add(val);
2228#ifdef CONFIG_DEBUG_PREEMPT 2341#ifdef CONFIG_DEBUG_PREEMPT
2229 /* 2342 /*
2230 * Spinlock count overflowing soon? 2343 * Spinlock count overflowing soon?
@@ -2235,9 +2348,9 @@ void __kprobes add_preempt_count(int val)
2235 if (preempt_count() == val) 2348 if (preempt_count() == val)
2236 trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); 2349 trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2237} 2350}
2238EXPORT_SYMBOL(add_preempt_count); 2351EXPORT_SYMBOL(preempt_count_add);
2239 2352
2240void __kprobes sub_preempt_count(int val) 2353void __kprobes preempt_count_sub(int val)
2241{ 2354{
2242#ifdef CONFIG_DEBUG_PREEMPT 2355#ifdef CONFIG_DEBUG_PREEMPT
2243 /* 2356 /*
@@ -2255,9 +2368,9 @@ void __kprobes sub_preempt_count(int val)
2255 2368
2256 if (preempt_count() == val) 2369 if (preempt_count() == val)
2257 trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); 2370 trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
2258 preempt_count() -= val; 2371 __preempt_count_sub(val);
2259} 2372}
2260EXPORT_SYMBOL(sub_preempt_count); 2373EXPORT_SYMBOL(preempt_count_sub);
2261 2374
2262#endif 2375#endif
2263 2376
@@ -2430,6 +2543,7 @@ need_resched:
2430 put_prev_task(rq, prev); 2543 put_prev_task(rq, prev);
2431 next = pick_next_task(rq); 2544 next = pick_next_task(rq);
2432 clear_tsk_need_resched(prev); 2545 clear_tsk_need_resched(prev);
2546 clear_preempt_need_resched();
2433 rq->skip_clock_update = 0; 2547 rq->skip_clock_update = 0;
2434 2548
2435 if (likely(prev != next)) { 2549 if (likely(prev != next)) {
@@ -2520,9 +2634,9 @@ asmlinkage void __sched notrace preempt_schedule(void)
2520 return; 2634 return;
2521 2635
2522 do { 2636 do {
2523 add_preempt_count_notrace(PREEMPT_ACTIVE); 2637 __preempt_count_add(PREEMPT_ACTIVE);
2524 __schedule(); 2638 __schedule();
2525 sub_preempt_count_notrace(PREEMPT_ACTIVE); 2639 __preempt_count_sub(PREEMPT_ACTIVE);
2526 2640
2527 /* 2641 /*
2528 * Check again in case we missed a preemption opportunity 2642 * Check again in case we missed a preemption opportunity
@@ -2541,20 +2655,19 @@ EXPORT_SYMBOL(preempt_schedule);
2541 */ 2655 */
2542asmlinkage void __sched preempt_schedule_irq(void) 2656asmlinkage void __sched preempt_schedule_irq(void)
2543{ 2657{
2544 struct thread_info *ti = current_thread_info();
2545 enum ctx_state prev_state; 2658 enum ctx_state prev_state;
2546 2659
2547 /* Catch callers which need to be fixed */ 2660 /* Catch callers which need to be fixed */
2548 BUG_ON(ti->preempt_count || !irqs_disabled()); 2661 BUG_ON(preempt_count() || !irqs_disabled());
2549 2662
2550 prev_state = exception_enter(); 2663 prev_state = exception_enter();
2551 2664
2552 do { 2665 do {
2553 add_preempt_count(PREEMPT_ACTIVE); 2666 __preempt_count_add(PREEMPT_ACTIVE);
2554 local_irq_enable(); 2667 local_irq_enable();
2555 __schedule(); 2668 __schedule();
2556 local_irq_disable(); 2669 local_irq_disable();
2557 sub_preempt_count(PREEMPT_ACTIVE); 2670 __preempt_count_sub(PREEMPT_ACTIVE);
2558 2671
2559 /* 2672 /*
2560 * Check again in case we missed a preemption opportunity 2673 * Check again in case we missed a preemption opportunity
@@ -2575,393 +2688,6 @@ int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
2575} 2688}
2576EXPORT_SYMBOL(default_wake_function); 2689EXPORT_SYMBOL(default_wake_function);
2577 2690
2578/*
2579 * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
2580 * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
2581 * number) then we wake all the non-exclusive tasks and one exclusive task.
2582 *
2583 * There are circumstances in which we can try to wake a task which has already
2584 * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
2585 * zero in this (rare) case, and we handle it by continuing to scan the queue.
2586 */
2587static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
2588 int nr_exclusive, int wake_flags, void *key)
2589{
2590 wait_queue_t *curr, *next;
2591
2592 list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
2593 unsigned flags = curr->flags;
2594
2595 if (curr->func(curr, mode, wake_flags, key) &&
2596 (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
2597 break;
2598 }
2599}
2600
2601/**
2602 * __wake_up - wake up threads blocked on a waitqueue.
2603 * @q: the waitqueue
2604 * @mode: which threads
2605 * @nr_exclusive: how many wake-one or wake-many threads to wake up
2606 * @key: is directly passed to the wakeup function
2607 *
2608 * It may be assumed that this function implies a write memory barrier before
2609 * changing the task state if and only if any tasks are woken up.
2610 */
2611void __wake_up(wait_queue_head_t *q, unsigned int mode,
2612 int nr_exclusive, void *key)
2613{
2614 unsigned long flags;
2615
2616 spin_lock_irqsave(&q->lock, flags);
2617 __wake_up_common(q, mode, nr_exclusive, 0, key);
2618 spin_unlock_irqrestore(&q->lock, flags);
2619}
2620EXPORT_SYMBOL(__wake_up);
2621
2622/*
2623 * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
2624 */
2625void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
2626{
2627 __wake_up_common(q, mode, nr, 0, NULL);
2628}
2629EXPORT_SYMBOL_GPL(__wake_up_locked);
2630
2631void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
2632{
2633 __wake_up_common(q, mode, 1, 0, key);
2634}
2635EXPORT_SYMBOL_GPL(__wake_up_locked_key);
2636
2637/**
2638 * __wake_up_sync_key - wake up threads blocked on a waitqueue.
2639 * @q: the waitqueue
2640 * @mode: which threads
2641 * @nr_exclusive: how many wake-one or wake-many threads to wake up
2642 * @key: opaque value to be passed to wakeup targets
2643 *
2644 * The sync wakeup differs that the waker knows that it will schedule
2645 * away soon, so while the target thread will be woken up, it will not
2646 * be migrated to another CPU - ie. the two threads are 'synchronized'
2647 * with each other. This can prevent needless bouncing between CPUs.
2648 *
2649 * On UP it can prevent extra preemption.
2650 *
2651 * It may be assumed that this function implies a write memory barrier before
2652 * changing the task state if and only if any tasks are woken up.
2653 */
2654void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
2655 int nr_exclusive, void *key)
2656{
2657 unsigned long flags;
2658 int wake_flags = WF_SYNC;
2659
2660 if (unlikely(!q))
2661 return;
2662
2663 if (unlikely(nr_exclusive != 1))
2664 wake_flags = 0;
2665
2666 spin_lock_irqsave(&q->lock, flags);
2667 __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
2668 spin_unlock_irqrestore(&q->lock, flags);
2669}
2670EXPORT_SYMBOL_GPL(__wake_up_sync_key);
2671
2672/*
2673 * __wake_up_sync - see __wake_up_sync_key()
2674 */
2675void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
2676{
2677 __wake_up_sync_key(q, mode, nr_exclusive, NULL);
2678}
2679EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
2680
2681/**
2682 * complete: - signals a single thread waiting on this completion
2683 * @x: holds the state of this particular completion
2684 *
2685 * This will wake up a single thread waiting on this completion. Threads will be
2686 * awakened in the same order in which they were queued.
2687 *
2688 * See also complete_all(), wait_for_completion() and related routines.
2689 *
2690 * It may be assumed that this function implies a write memory barrier before
2691 * changing the task state if and only if any tasks are woken up.
2692 */
2693void complete(struct completion *x)
2694{
2695 unsigned long flags;
2696
2697 spin_lock_irqsave(&x->wait.lock, flags);
2698 x->done++;
2699 __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
2700 spin_unlock_irqrestore(&x->wait.lock, flags);
2701}
2702EXPORT_SYMBOL(complete);
2703
2704/**
2705 * complete_all: - signals all threads waiting on this completion
2706 * @x: holds the state of this particular completion
2707 *
2708 * This will wake up all threads waiting on this particular completion event.
2709 *
2710 * It may be assumed that this function implies a write memory barrier before
2711 * changing the task state if and only if any tasks are woken up.
2712 */
2713void complete_all(struct completion *x)
2714{
2715 unsigned long flags;
2716
2717 spin_lock_irqsave(&x->wait.lock, flags);
2718 x->done += UINT_MAX/2;
2719 __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
2720 spin_unlock_irqrestore(&x->wait.lock, flags);
2721}
2722EXPORT_SYMBOL(complete_all);
2723
2724static inline long __sched
2725do_wait_for_common(struct completion *x,
2726 long (*action)(long), long timeout, int state)
2727{
2728 if (!x->done) {
2729 DECLARE_WAITQUEUE(wait, current);
2730
2731 __add_wait_queue_tail_exclusive(&x->wait, &wait);
2732 do {
2733 if (signal_pending_state(state, current)) {
2734 timeout = -ERESTARTSYS;
2735 break;
2736 }
2737 __set_current_state(state);
2738 spin_unlock_irq(&x->wait.lock);
2739 timeout = action(timeout);
2740 spin_lock_irq(&x->wait.lock);
2741 } while (!x->done && timeout);
2742 __remove_wait_queue(&x->wait, &wait);
2743 if (!x->done)
2744 return timeout;
2745 }
2746 x->done--;
2747 return timeout ?: 1;
2748}
2749
2750static inline long __sched
2751__wait_for_common(struct completion *x,
2752 long (*action)(long), long timeout, int state)
2753{
2754 might_sleep();
2755
2756 spin_lock_irq(&x->wait.lock);
2757 timeout = do_wait_for_common(x, action, timeout, state);
2758 spin_unlock_irq(&x->wait.lock);
2759 return timeout;
2760}
2761
2762static long __sched
2763wait_for_common(struct completion *x, long timeout, int state)
2764{
2765 return __wait_for_common(x, schedule_timeout, timeout, state);
2766}
2767
2768static long __sched
2769wait_for_common_io(struct completion *x, long timeout, int state)
2770{
2771 return __wait_for_common(x, io_schedule_timeout, timeout, state);
2772}
2773
2774/**
2775 * wait_for_completion: - waits for completion of a task
2776 * @x: holds the state of this particular completion
2777 *
2778 * This waits to be signaled for completion of a specific task. It is NOT
2779 * interruptible and there is no timeout.
2780 *
2781 * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
2782 * and interrupt capability. Also see complete().
2783 */
2784void __sched wait_for_completion(struct completion *x)
2785{
2786 wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
2787}
2788EXPORT_SYMBOL(wait_for_completion);
2789
2790/**
2791 * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
2792 * @x: holds the state of this particular completion
2793 * @timeout: timeout value in jiffies
2794 *
2795 * This waits for either a completion of a specific task to be signaled or for a
2796 * specified timeout to expire. The timeout is in jiffies. It is not
2797 * interruptible.
2798 *
2799 * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
2800 * till timeout) if completed.
2801 */
2802unsigned long __sched
2803wait_for_completion_timeout(struct completion *x, unsigned long timeout)
2804{
2805 return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
2806}
2807EXPORT_SYMBOL(wait_for_completion_timeout);
2808
2809/**
2810 * wait_for_completion_io: - waits for completion of a task
2811 * @x: holds the state of this particular completion
2812 *
2813 * This waits to be signaled for completion of a specific task. It is NOT
2814 * interruptible and there is no timeout. The caller is accounted as waiting
2815 * for IO.
2816 */
2817void __sched wait_for_completion_io(struct completion *x)
2818{
2819 wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
2820}
2821EXPORT_SYMBOL(wait_for_completion_io);
2822
2823/**
2824 * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
2825 * @x: holds the state of this particular completion
2826 * @timeout: timeout value in jiffies
2827 *
2828 * This waits for either a completion of a specific task to be signaled or for a
2829 * specified timeout to expire. The timeout is in jiffies. It is not
2830 * interruptible. The caller is accounted as waiting for IO.
2831 *
2832 * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
2833 * till timeout) if completed.
2834 */
2835unsigned long __sched
2836wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
2837{
2838 return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
2839}
2840EXPORT_SYMBOL(wait_for_completion_io_timeout);
2841
2842/**
2843 * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
2844 * @x: holds the state of this particular completion
2845 *
2846 * This waits for completion of a specific task to be signaled. It is
2847 * interruptible.
2848 *
2849 * Return: -ERESTARTSYS if interrupted, 0 if completed.
2850 */
2851int __sched wait_for_completion_interruptible(struct completion *x)
2852{
2853 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
2854 if (t == -ERESTARTSYS)
2855 return t;
2856 return 0;
2857}
2858EXPORT_SYMBOL(wait_for_completion_interruptible);
2859
2860/**
2861 * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
2862 * @x: holds the state of this particular completion
2863 * @timeout: timeout value in jiffies
2864 *
2865 * This waits for either a completion of a specific task to be signaled or for a
2866 * specified timeout to expire. It is interruptible. The timeout is in jiffies.
2867 *
2868 * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
2869 * or number of jiffies left till timeout) if completed.
2870 */
2871long __sched
2872wait_for_completion_interruptible_timeout(struct completion *x,
2873 unsigned long timeout)
2874{
2875 return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
2876}
2877EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
2878
2879/**
2880 * wait_for_completion_killable: - waits for completion of a task (killable)
2881 * @x: holds the state of this particular completion
2882 *
2883 * This waits to be signaled for completion of a specific task. It can be
2884 * interrupted by a kill signal.
2885 *
2886 * Return: -ERESTARTSYS if interrupted, 0 if completed.
2887 */
2888int __sched wait_for_completion_killable(struct completion *x)
2889{
2890 long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
2891 if (t == -ERESTARTSYS)
2892 return t;
2893 return 0;
2894}
2895EXPORT_SYMBOL(wait_for_completion_killable);
2896
2897/**
2898 * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
2899 * @x: holds the state of this particular completion
2900 * @timeout: timeout value in jiffies
2901 *
2902 * This waits for either a completion of a specific task to be
2903 * signaled or for a specified timeout to expire. It can be
2904 * interrupted by a kill signal. The timeout is in jiffies.
2905 *
2906 * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
2907 * or number of jiffies left till timeout) if completed.
2908 */
2909long __sched
2910wait_for_completion_killable_timeout(struct completion *x,
2911 unsigned long timeout)
2912{
2913 return wait_for_common(x, timeout, TASK_KILLABLE);
2914}
2915EXPORT_SYMBOL(wait_for_completion_killable_timeout);
2916
2917/**
2918 * try_wait_for_completion - try to decrement a completion without blocking
2919 * @x: completion structure
2920 *
2921 * Return: 0 if a decrement cannot be done without blocking
2922 * 1 if a decrement succeeded.
2923 *
2924 * If a completion is being used as a counting completion,
2925 * attempt to decrement the counter without blocking. This
2926 * enables us to avoid waiting if the resource the completion
2927 * is protecting is not available.
2928 */
2929bool try_wait_for_completion(struct completion *x)
2930{
2931 unsigned long flags;
2932 int ret = 1;
2933
2934 spin_lock_irqsave(&x->wait.lock, flags);
2935 if (!x->done)
2936 ret = 0;
2937 else
2938 x->done--;
2939 spin_unlock_irqrestore(&x->wait.lock, flags);
2940 return ret;
2941}
2942EXPORT_SYMBOL(try_wait_for_completion);
2943
2944/**
2945 * completion_done - Test to see if a completion has any waiters
2946 * @x: completion structure
2947 *
2948 * Return: 0 if there are waiters (wait_for_completion() in progress)
2949 * 1 if there are no waiters.
2950 *
2951 */
2952bool completion_done(struct completion *x)
2953{
2954 unsigned long flags;
2955 int ret = 1;
2956
2957 spin_lock_irqsave(&x->wait.lock, flags);
2958 if (!x->done)
2959 ret = 0;
2960 spin_unlock_irqrestore(&x->wait.lock, flags);
2961 return ret;
2962}
2963EXPORT_SYMBOL(completion_done);
2964
2965static long __sched 2691static long __sched
2966sleep_on_common(wait_queue_head_t *q, int state, long timeout) 2692sleep_on_common(wait_queue_head_t *q, int state, long timeout)
2967{ 2693{
@@ -3598,13 +3324,11 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
3598 struct task_struct *p; 3324 struct task_struct *p;
3599 int retval; 3325 int retval;
3600 3326
3601 get_online_cpus();
3602 rcu_read_lock(); 3327 rcu_read_lock();
3603 3328
3604 p = find_process_by_pid(pid); 3329 p = find_process_by_pid(pid);
3605 if (!p) { 3330 if (!p) {
3606 rcu_read_unlock(); 3331 rcu_read_unlock();
3607 put_online_cpus();
3608 return -ESRCH; 3332 return -ESRCH;
3609 } 3333 }
3610 3334
@@ -3661,7 +3385,6 @@ out_free_cpus_allowed:
3661 free_cpumask_var(cpus_allowed); 3385 free_cpumask_var(cpus_allowed);
3662out_put_task: 3386out_put_task:
3663 put_task_struct(p); 3387 put_task_struct(p);
3664 put_online_cpus();
3665 return retval; 3388 return retval;
3666} 3389}
3667 3390
@@ -3706,7 +3429,6 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
3706 unsigned long flags; 3429 unsigned long flags;
3707 int retval; 3430 int retval;
3708 3431
3709 get_online_cpus();
3710 rcu_read_lock(); 3432 rcu_read_lock();
3711 3433
3712 retval = -ESRCH; 3434 retval = -ESRCH;
@@ -3719,12 +3441,11 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
3719 goto out_unlock; 3441 goto out_unlock;
3720 3442
3721 raw_spin_lock_irqsave(&p->pi_lock, flags); 3443 raw_spin_lock_irqsave(&p->pi_lock, flags);
3722 cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); 3444 cpumask_and(mask, &p->cpus_allowed, cpu_active_mask);
3723 raw_spin_unlock_irqrestore(&p->pi_lock, flags); 3445 raw_spin_unlock_irqrestore(&p->pi_lock, flags);
3724 3446
3725out_unlock: 3447out_unlock:
3726 rcu_read_unlock(); 3448 rcu_read_unlock();
3727 put_online_cpus();
3728 3449
3729 return retval; 3450 return retval;
3730} 3451}
@@ -3794,16 +3515,11 @@ SYSCALL_DEFINE0(sched_yield)
3794 return 0; 3515 return 0;
3795} 3516}
3796 3517
3797static inline int should_resched(void)
3798{
3799 return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
3800}
3801
3802static void __cond_resched(void) 3518static void __cond_resched(void)
3803{ 3519{
3804 add_preempt_count(PREEMPT_ACTIVE); 3520 __preempt_count_add(PREEMPT_ACTIVE);
3805 __schedule(); 3521 __schedule();
3806 sub_preempt_count(PREEMPT_ACTIVE); 3522 __preempt_count_sub(PREEMPT_ACTIVE);
3807} 3523}
3808 3524
3809int __sched _cond_resched(void) 3525int __sched _cond_resched(void)
@@ -4186,7 +3902,7 @@ void init_idle(struct task_struct *idle, int cpu)
4186 3902
4187 raw_spin_lock_irqsave(&rq->lock, flags); 3903 raw_spin_lock_irqsave(&rq->lock, flags);
4188 3904
4189 __sched_fork(idle); 3905 __sched_fork(0, idle);
4190 idle->state = TASK_RUNNING; 3906 idle->state = TASK_RUNNING;
4191 idle->se.exec_start = sched_clock(); 3907 idle->se.exec_start = sched_clock();
4192 3908
@@ -4212,7 +3928,7 @@ void init_idle(struct task_struct *idle, int cpu)
4212 raw_spin_unlock_irqrestore(&rq->lock, flags); 3928 raw_spin_unlock_irqrestore(&rq->lock, flags);
4213 3929
4214 /* Set the preempt count _outside_ the spinlocks! */ 3930 /* Set the preempt count _outside_ the spinlocks! */
4215 task_thread_info(idle)->preempt_count = 0; 3931 init_idle_preempt_count(idle, cpu);
4216 3932
4217 /* 3933 /*
4218 * The idle tasks have their own, simple scheduling class: 3934 * The idle tasks have their own, simple scheduling class:
@@ -4346,6 +4062,53 @@ fail:
4346 return ret; 4062 return ret;
4347} 4063}
4348 4064
4065#ifdef CONFIG_NUMA_BALANCING
4066/* Migrate current task p to target_cpu */
4067int migrate_task_to(struct task_struct *p, int target_cpu)
4068{
4069 struct migration_arg arg = { p, target_cpu };
4070 int curr_cpu = task_cpu(p);
4071
4072 if (curr_cpu == target_cpu)
4073 return 0;
4074
4075 if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p)))
4076 return -EINVAL;
4077
4078 /* TODO: This is not properly updating schedstats */
4079
4080 return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg);
4081}
4082
4083/*
4084 * Requeue a task on a given node and accurately track the number of NUMA
4085 * tasks on the runqueues
4086 */
4087void sched_setnuma(struct task_struct *p, int nid)
4088{
4089 struct rq *rq;
4090 unsigned long flags;
4091 bool on_rq, running;
4092
4093 rq = task_rq_lock(p, &flags);
4094 on_rq = p->on_rq;
4095 running = task_current(rq, p);
4096
4097 if (on_rq)
4098 dequeue_task(rq, p, 0);
4099 if (running)
4100 p->sched_class->put_prev_task(rq, p);
4101
4102 p->numa_preferred_nid = nid;
4103
4104 if (running)
4105 p->sched_class->set_curr_task(rq);
4106 if (on_rq)
4107 enqueue_task(rq, p, 0);
4108 task_rq_unlock(rq, p, &flags);
4109}
4110#endif
4111
4349/* 4112/*
4350 * migration_cpu_stop - this will be executed by a highprio stopper thread 4113 * migration_cpu_stop - this will be executed by a highprio stopper thread
4351 * and performs thread migration by bumping thread off CPU then 4114 * and performs thread migration by bumping thread off CPU then
@@ -5119,6 +4882,9 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu)
5119DEFINE_PER_CPU(struct sched_domain *, sd_llc); 4882DEFINE_PER_CPU(struct sched_domain *, sd_llc);
5120DEFINE_PER_CPU(int, sd_llc_size); 4883DEFINE_PER_CPU(int, sd_llc_size);
5121DEFINE_PER_CPU(int, sd_llc_id); 4884DEFINE_PER_CPU(int, sd_llc_id);
4885DEFINE_PER_CPU(struct sched_domain *, sd_numa);
4886DEFINE_PER_CPU(struct sched_domain *, sd_busy);
4887DEFINE_PER_CPU(struct sched_domain *, sd_asym);
5122 4888
5123static void update_top_cache_domain(int cpu) 4889static void update_top_cache_domain(int cpu)
5124{ 4890{
@@ -5130,11 +4896,18 @@ static void update_top_cache_domain(int cpu)
5130 if (sd) { 4896 if (sd) {
5131 id = cpumask_first(sched_domain_span(sd)); 4897 id = cpumask_first(sched_domain_span(sd));
5132 size = cpumask_weight(sched_domain_span(sd)); 4898 size = cpumask_weight(sched_domain_span(sd));
4899 rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent);
5133 } 4900 }
5134 4901
5135 rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); 4902 rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
5136 per_cpu(sd_llc_size, cpu) = size; 4903 per_cpu(sd_llc_size, cpu) = size;
5137 per_cpu(sd_llc_id, cpu) = id; 4904 per_cpu(sd_llc_id, cpu) = id;
4905
4906 sd = lowest_flag_domain(cpu, SD_NUMA);
4907 rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
4908
4909 sd = highest_flag_domain(cpu, SD_ASYM_PACKING);
4910 rcu_assign_pointer(per_cpu(sd_asym, cpu), sd);
5138} 4911}
5139 4912
5140/* 4913/*
@@ -5654,6 +5427,7 @@ sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
5654 | 0*SD_SHARE_PKG_RESOURCES 5427 | 0*SD_SHARE_PKG_RESOURCES
5655 | 1*SD_SERIALIZE 5428 | 1*SD_SERIALIZE
5656 | 0*SD_PREFER_SIBLING 5429 | 0*SD_PREFER_SIBLING
5430 | 1*SD_NUMA
5657 | sd_local_flags(level) 5431 | sd_local_flags(level)
5658 , 5432 ,
5659 .last_balance = jiffies, 5433 .last_balance = jiffies,
@@ -6335,14 +6109,17 @@ void __init sched_init_smp(void)
6335 6109
6336 sched_init_numa(); 6110 sched_init_numa();
6337 6111
6338 get_online_cpus(); 6112 /*
6113 * There's no userspace yet to cause hotplug operations; hence all the
6114 * cpu masks are stable and all blatant races in the below code cannot
6115 * happen.
6116 */
6339 mutex_lock(&sched_domains_mutex); 6117 mutex_lock(&sched_domains_mutex);
6340 init_sched_domains(cpu_active_mask); 6118 init_sched_domains(cpu_active_mask);
6341 cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); 6119 cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
6342 if (cpumask_empty(non_isolated_cpus)) 6120 if (cpumask_empty(non_isolated_cpus))
6343 cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); 6121 cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
6344 mutex_unlock(&sched_domains_mutex); 6122 mutex_unlock(&sched_domains_mutex);
6345 put_online_cpus();
6346 6123
6347 hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); 6124 hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
6348 hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); 6125 hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
@@ -6505,6 +6282,7 @@ void __init sched_init(void)
6505 rq->online = 0; 6282 rq->online = 0;
6506 rq->idle_stamp = 0; 6283 rq->idle_stamp = 0;
6507 rq->avg_idle = 2*sysctl_sched_migration_cost; 6284 rq->avg_idle = 2*sysctl_sched_migration_cost;
6285 rq->max_idle_balance_cost = sysctl_sched_migration_cost;
6508 6286
6509 INIT_LIST_HEAD(&rq->cfs_tasks); 6287 INIT_LIST_HEAD(&rq->cfs_tasks);
6510 6288
@@ -7277,7 +7055,12 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
7277 7055
7278 runtime_enabled = quota != RUNTIME_INF; 7056 runtime_enabled = quota != RUNTIME_INF;
7279 runtime_was_enabled = cfs_b->quota != RUNTIME_INF; 7057 runtime_was_enabled = cfs_b->quota != RUNTIME_INF;
7280 account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled); 7058 /*
7059 * If we need to toggle cfs_bandwidth_used, off->on must occur
7060 * before making related changes, and on->off must occur afterwards
7061 */
7062 if (runtime_enabled && !runtime_was_enabled)
7063 cfs_bandwidth_usage_inc();
7281 raw_spin_lock_irq(&cfs_b->lock); 7064 raw_spin_lock_irq(&cfs_b->lock);
7282 cfs_b->period = ns_to_ktime(period); 7065 cfs_b->period = ns_to_ktime(period);
7283 cfs_b->quota = quota; 7066 cfs_b->quota = quota;
@@ -7303,6 +7086,8 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
7303 unthrottle_cfs_rq(cfs_rq); 7086 unthrottle_cfs_rq(cfs_rq);
7304 raw_spin_unlock_irq(&rq->lock); 7087 raw_spin_unlock_irq(&rq->lock);
7305 } 7088 }
7089 if (runtime_was_enabled && !runtime_enabled)
7090 cfs_bandwidth_usage_dec();
7306out_unlock: 7091out_unlock:
7307 mutex_unlock(&cfs_constraints_mutex); 7092 mutex_unlock(&cfs_constraints_mutex);
7308 7093
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 196559994f7c..5c34d1817e8f 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -15,6 +15,7 @@
15#include <linux/seq_file.h> 15#include <linux/seq_file.h>
16#include <linux/kallsyms.h> 16#include <linux/kallsyms.h>
17#include <linux/utsname.h> 17#include <linux/utsname.h>
18#include <linux/mempolicy.h>
18 19
19#include "sched.h" 20#include "sched.h"
20 21
@@ -137,6 +138,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
137 SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld", 138 SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
138 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L); 139 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
139#endif 140#endif
141#ifdef CONFIG_NUMA_BALANCING
142 SEQ_printf(m, " %d", cpu_to_node(task_cpu(p)));
143#endif
140#ifdef CONFIG_CGROUP_SCHED 144#ifdef CONFIG_CGROUP_SCHED
141 SEQ_printf(m, " %s", task_group_path(task_group(p))); 145 SEQ_printf(m, " %s", task_group_path(task_group(p)));
142#endif 146#endif
@@ -159,7 +163,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
159 read_lock_irqsave(&tasklist_lock, flags); 163 read_lock_irqsave(&tasklist_lock, flags);
160 164
161 do_each_thread(g, p) { 165 do_each_thread(g, p) {
162 if (!p->on_rq || task_cpu(p) != rq_cpu) 166 if (task_cpu(p) != rq_cpu)
163 continue; 167 continue;
164 168
165 print_task(m, rq, p); 169 print_task(m, rq, p);
@@ -225,6 +229,14 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
225 atomic_read(&cfs_rq->tg->runnable_avg)); 229 atomic_read(&cfs_rq->tg->runnable_avg));
226#endif 230#endif
227#endif 231#endif
232#ifdef CONFIG_CFS_BANDWIDTH
233 SEQ_printf(m, " .%-30s: %d\n", "tg->cfs_bandwidth.timer_active",
234 cfs_rq->tg->cfs_bandwidth.timer_active);
235 SEQ_printf(m, " .%-30s: %d\n", "throttled",
236 cfs_rq->throttled);
237 SEQ_printf(m, " .%-30s: %d\n", "throttle_count",
238 cfs_rq->throttle_count);
239#endif
228 240
229#ifdef CONFIG_FAIR_GROUP_SCHED 241#ifdef CONFIG_FAIR_GROUP_SCHED
230 print_cfs_group_stats(m, cpu, cfs_rq->tg); 242 print_cfs_group_stats(m, cpu, cfs_rq->tg);
@@ -345,7 +357,7 @@ static void sched_debug_header(struct seq_file *m)
345 cpu_clk = local_clock(); 357 cpu_clk = local_clock();
346 local_irq_restore(flags); 358 local_irq_restore(flags);
347 359
348 SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n", 360 SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n",
349 init_utsname()->release, 361 init_utsname()->release,
350 (int)strcspn(init_utsname()->version, " "), 362 (int)strcspn(init_utsname()->version, " "),
351 init_utsname()->version); 363 init_utsname()->version);
@@ -488,6 +500,56 @@ static int __init init_sched_debug_procfs(void)
488 500
489__initcall(init_sched_debug_procfs); 501__initcall(init_sched_debug_procfs);
490 502
503#define __P(F) \
504 SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
505#define P(F) \
506 SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
507#define __PN(F) \
508 SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
509#define PN(F) \
510 SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
511
512
513static void sched_show_numa(struct task_struct *p, struct seq_file *m)
514{
515#ifdef CONFIG_NUMA_BALANCING
516 struct mempolicy *pol;
517 int node, i;
518
519 if (p->mm)
520 P(mm->numa_scan_seq);
521
522 task_lock(p);
523 pol = p->mempolicy;
524 if (pol && !(pol->flags & MPOL_F_MORON))
525 pol = NULL;
526 mpol_get(pol);
527 task_unlock(p);
528
529 SEQ_printf(m, "numa_migrations, %ld\n", xchg(&p->numa_pages_migrated, 0));
530
531 for_each_online_node(node) {
532 for (i = 0; i < 2; i++) {
533 unsigned long nr_faults = -1;
534 int cpu_current, home_node;
535
536 if (p->numa_faults)
537 nr_faults = p->numa_faults[2*node + i];
538
539 cpu_current = !i ? (task_node(p) == node) :
540 (pol && node_isset(node, pol->v.nodes));
541
542 home_node = (p->numa_preferred_nid == node);
543
544 SEQ_printf(m, "numa_faults, %d, %d, %d, %d, %ld\n",
545 i, node, cpu_current, home_node, nr_faults);
546 }
547 }
548
549 mpol_put(pol);
550#endif
551}
552
491void proc_sched_show_task(struct task_struct *p, struct seq_file *m) 553void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
492{ 554{
493 unsigned long nr_switches; 555 unsigned long nr_switches;
@@ -591,6 +653,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
591 SEQ_printf(m, "%-45s:%21Ld\n", 653 SEQ_printf(m, "%-45s:%21Ld\n",
592 "clock-delta", (long long)(t1-t0)); 654 "clock-delta", (long long)(t1-t0));
593 } 655 }
656
657 sched_show_numa(p, m);
594} 658}
595 659
596void proc_sched_set_task(struct task_struct *p) 660void proc_sched_set_task(struct task_struct *p)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7c70201fbc61..df77c605c7a6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -681,6 +681,8 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
681} 681}
682 682
683#ifdef CONFIG_SMP 683#ifdef CONFIG_SMP
684static unsigned long task_h_load(struct task_struct *p);
685
684static inline void __update_task_entity_contrib(struct sched_entity *se); 686static inline void __update_task_entity_contrib(struct sched_entity *se);
685 687
686/* Give new task start runnable values to heavy its load in infant time */ 688/* Give new task start runnable values to heavy its load in infant time */
@@ -818,11 +820,12 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
818 820
819#ifdef CONFIG_NUMA_BALANCING 821#ifdef CONFIG_NUMA_BALANCING
820/* 822/*
821 * numa task sample period in ms 823 * Approximate time to scan a full NUMA task in ms. The task scan period is
824 * calculated based on the tasks virtual memory size and
825 * numa_balancing_scan_size.
822 */ 826 */
823unsigned int sysctl_numa_balancing_scan_period_min = 100; 827unsigned int sysctl_numa_balancing_scan_period_min = 1000;
824unsigned int sysctl_numa_balancing_scan_period_max = 100*50; 828unsigned int sysctl_numa_balancing_scan_period_max = 60000;
825unsigned int sysctl_numa_balancing_scan_period_reset = 100*600;
826 829
827/* Portion of address space to scan in MB */ 830/* Portion of address space to scan in MB */
828unsigned int sysctl_numa_balancing_scan_size = 256; 831unsigned int sysctl_numa_balancing_scan_size = 256;
@@ -830,41 +833,810 @@ unsigned int sysctl_numa_balancing_scan_size = 256;
830/* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */ 833/* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */
831unsigned int sysctl_numa_balancing_scan_delay = 1000; 834unsigned int sysctl_numa_balancing_scan_delay = 1000;
832 835
833static void task_numa_placement(struct task_struct *p) 836/*
837 * After skipping a page migration on a shared page, skip N more numa page
838 * migrations unconditionally. This reduces the number of NUMA migrations
839 * in shared memory workloads, and has the effect of pulling tasks towards
840 * where their memory lives, over pulling the memory towards the task.
841 */
842unsigned int sysctl_numa_balancing_migrate_deferred = 16;
843
844static unsigned int task_nr_scan_windows(struct task_struct *p)
845{
846 unsigned long rss = 0;
847 unsigned long nr_scan_pages;
848
849 /*
850 * Calculations based on RSS as non-present and empty pages are skipped
851 * by the PTE scanner and NUMA hinting faults should be trapped based
852 * on resident pages
853 */
854 nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT);
855 rss = get_mm_rss(p->mm);
856 if (!rss)
857 rss = nr_scan_pages;
858
859 rss = round_up(rss, nr_scan_pages);
860 return rss / nr_scan_pages;
861}
862
863/* For sanitys sake, never scan more PTEs than MAX_SCAN_WINDOW MB/sec. */
864#define MAX_SCAN_WINDOW 2560
865
866static unsigned int task_scan_min(struct task_struct *p)
867{
868 unsigned int scan, floor;
869 unsigned int windows = 1;
870
871 if (sysctl_numa_balancing_scan_size < MAX_SCAN_WINDOW)
872 windows = MAX_SCAN_WINDOW / sysctl_numa_balancing_scan_size;
873 floor = 1000 / windows;
874
875 scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p);
876 return max_t(unsigned int, floor, scan);
877}
878
879static unsigned int task_scan_max(struct task_struct *p)
880{
881 unsigned int smin = task_scan_min(p);
882 unsigned int smax;
883
884 /* Watch for min being lower than max due to floor calculations */
885 smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p);
886 return max(smin, smax);
887}
888
889/*
890 * Once a preferred node is selected the scheduler balancer will prefer moving
891 * a task to that node for sysctl_numa_balancing_settle_count number of PTE
892 * scans. This will give the process the chance to accumulate more faults on
893 * the preferred node but still allow the scheduler to move the task again if
894 * the nodes CPUs are overloaded.
895 */
896unsigned int sysctl_numa_balancing_settle_count __read_mostly = 4;
897
898static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
899{
900 rq->nr_numa_running += (p->numa_preferred_nid != -1);
901 rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p));
902}
903
904static void account_numa_dequeue(struct rq *rq, struct task_struct *p)
905{
906 rq->nr_numa_running -= (p->numa_preferred_nid != -1);
907 rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p));
908}
909
910struct numa_group {
911 atomic_t refcount;
912
913 spinlock_t lock; /* nr_tasks, tasks */
914 int nr_tasks;
915 pid_t gid;
916 struct list_head task_list;
917
918 struct rcu_head rcu;
919 unsigned long total_faults;
920 unsigned long faults[0];
921};
922
923pid_t task_numa_group_id(struct task_struct *p)
924{
925 return p->numa_group ? p->numa_group->gid : 0;
926}
927
928static inline int task_faults_idx(int nid, int priv)
929{
930 return 2 * nid + priv;
931}
932
933static inline unsigned long task_faults(struct task_struct *p, int nid)
934{
935 if (!p->numa_faults)
936 return 0;
937
938 return p->numa_faults[task_faults_idx(nid, 0)] +
939 p->numa_faults[task_faults_idx(nid, 1)];
940}
941
942static inline unsigned long group_faults(struct task_struct *p, int nid)
943{
944 if (!p->numa_group)
945 return 0;
946
947 return p->numa_group->faults[2*nid] + p->numa_group->faults[2*nid+1];
948}
949
950/*
951 * These return the fraction of accesses done by a particular task, or
952 * task group, on a particular numa node. The group weight is given a
953 * larger multiplier, in order to group tasks together that are almost
954 * evenly spread out between numa nodes.
955 */
956static inline unsigned long task_weight(struct task_struct *p, int nid)
957{
958 unsigned long total_faults;
959
960 if (!p->numa_faults)
961 return 0;
962
963 total_faults = p->total_numa_faults;
964
965 if (!total_faults)
966 return 0;
967
968 return 1000 * task_faults(p, nid) / total_faults;
969}
970
971static inline unsigned long group_weight(struct task_struct *p, int nid)
834{ 972{
835 int seq; 973 if (!p->numa_group || !p->numa_group->total_faults)
974 return 0;
836 975
837 if (!p->mm) /* for example, ksmd faulting in a user's mm */ 976 return 1000 * group_faults(p, nid) / p->numa_group->total_faults;
977}
978
979static unsigned long weighted_cpuload(const int cpu);
980static unsigned long source_load(int cpu, int type);
981static unsigned long target_load(int cpu, int type);
982static unsigned long power_of(int cpu);
983static long effective_load(struct task_group *tg, int cpu, long wl, long wg);
984
985/* Cached statistics for all CPUs within a node */
986struct numa_stats {
987 unsigned long nr_running;
988 unsigned long load;
989
990 /* Total compute capacity of CPUs on a node */
991 unsigned long power;
992
993 /* Approximate capacity in terms of runnable tasks on a node */
994 unsigned long capacity;
995 int has_capacity;
996};
997
998/*
999 * XXX borrowed from update_sg_lb_stats
1000 */
1001static void update_numa_stats(struct numa_stats *ns, int nid)
1002{
1003 int cpu;
1004
1005 memset(ns, 0, sizeof(*ns));
1006 for_each_cpu(cpu, cpumask_of_node(nid)) {
1007 struct rq *rq = cpu_rq(cpu);
1008
1009 ns->nr_running += rq->nr_running;
1010 ns->load += weighted_cpuload(cpu);
1011 ns->power += power_of(cpu);
1012 }
1013
1014 ns->load = (ns->load * SCHED_POWER_SCALE) / ns->power;
1015 ns->capacity = DIV_ROUND_CLOSEST(ns->power, SCHED_POWER_SCALE);
1016 ns->has_capacity = (ns->nr_running < ns->capacity);
1017}
1018
1019struct task_numa_env {
1020 struct task_struct *p;
1021
1022 int src_cpu, src_nid;
1023 int dst_cpu, dst_nid;
1024
1025 struct numa_stats src_stats, dst_stats;
1026
1027 int imbalance_pct, idx;
1028
1029 struct task_struct *best_task;
1030 long best_imp;
1031 int best_cpu;
1032};
1033
1034static void task_numa_assign(struct task_numa_env *env,
1035 struct task_struct *p, long imp)
1036{
1037 if (env->best_task)
1038 put_task_struct(env->best_task);
1039 if (p)
1040 get_task_struct(p);
1041
1042 env->best_task = p;
1043 env->best_imp = imp;
1044 env->best_cpu = env->dst_cpu;
1045}
1046
1047/*
1048 * This checks if the overall compute and NUMA accesses of the system would
1049 * be improved if the source tasks was migrated to the target dst_cpu taking
1050 * into account that it might be best if task running on the dst_cpu should
1051 * be exchanged with the source task
1052 */
1053static void task_numa_compare(struct task_numa_env *env,
1054 long taskimp, long groupimp)
1055{
1056 struct rq *src_rq = cpu_rq(env->src_cpu);
1057 struct rq *dst_rq = cpu_rq(env->dst_cpu);
1058 struct task_struct *cur;
1059 long dst_load, src_load;
1060 long load;
1061 long imp = (groupimp > 0) ? groupimp : taskimp;
1062
1063 rcu_read_lock();
1064 cur = ACCESS_ONCE(dst_rq->curr);
1065 if (cur->pid == 0) /* idle */
1066 cur = NULL;
1067
1068 /*
1069 * "imp" is the fault differential for the source task between the
1070 * source and destination node. Calculate the total differential for
1071 * the source task and potential destination task. The more negative
1072 * the value is, the more rmeote accesses that would be expected to
1073 * be incurred if the tasks were swapped.
1074 */
1075 if (cur) {
1076 /* Skip this swap candidate if cannot move to the source cpu */
1077 if (!cpumask_test_cpu(env->src_cpu, tsk_cpus_allowed(cur)))
1078 goto unlock;
1079
1080 /*
1081 * If dst and source tasks are in the same NUMA group, or not
1082 * in any group then look only at task weights.
1083 */
1084 if (cur->numa_group == env->p->numa_group) {
1085 imp = taskimp + task_weight(cur, env->src_nid) -
1086 task_weight(cur, env->dst_nid);
1087 /*
1088 * Add some hysteresis to prevent swapping the
1089 * tasks within a group over tiny differences.
1090 */
1091 if (cur->numa_group)
1092 imp -= imp/16;
1093 } else {
1094 /*
1095 * Compare the group weights. If a task is all by
1096 * itself (not part of a group), use the task weight
1097 * instead.
1098 */
1099 if (env->p->numa_group)
1100 imp = groupimp;
1101 else
1102 imp = taskimp;
1103
1104 if (cur->numa_group)
1105 imp += group_weight(cur, env->src_nid) -
1106 group_weight(cur, env->dst_nid);
1107 else
1108 imp += task_weight(cur, env->src_nid) -
1109 task_weight(cur, env->dst_nid);
1110 }
1111 }
1112
1113 if (imp < env->best_imp)
1114 goto unlock;
1115
1116 if (!cur) {
1117 /* Is there capacity at our destination? */
1118 if (env->src_stats.has_capacity &&
1119 !env->dst_stats.has_capacity)
1120 goto unlock;
1121
1122 goto balance;
1123 }
1124
1125 /* Balance doesn't matter much if we're running a task per cpu */
1126 if (src_rq->nr_running == 1 && dst_rq->nr_running == 1)
1127 goto assign;
1128
1129 /*
1130 * In the overloaded case, try and keep the load balanced.
1131 */
1132balance:
1133 dst_load = env->dst_stats.load;
1134 src_load = env->src_stats.load;
1135
1136 /* XXX missing power terms */
1137 load = task_h_load(env->p);
1138 dst_load += load;
1139 src_load -= load;
1140
1141 if (cur) {
1142 load = task_h_load(cur);
1143 dst_load -= load;
1144 src_load += load;
1145 }
1146
1147 /* make src_load the smaller */
1148 if (dst_load < src_load)
1149 swap(dst_load, src_load);
1150
1151 if (src_load * env->imbalance_pct < dst_load * 100)
1152 goto unlock;
1153
1154assign:
1155 task_numa_assign(env, cur, imp);
1156unlock:
1157 rcu_read_unlock();
1158}
1159
1160static void task_numa_find_cpu(struct task_numa_env *env,
1161 long taskimp, long groupimp)
1162{
1163 int cpu;
1164
1165 for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
1166 /* Skip this CPU if the source task cannot migrate */
1167 if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(env->p)))
1168 continue;
1169
1170 env->dst_cpu = cpu;
1171 task_numa_compare(env, taskimp, groupimp);
1172 }
1173}
1174
1175static int task_numa_migrate(struct task_struct *p)
1176{
1177 struct task_numa_env env = {
1178 .p = p,
1179
1180 .src_cpu = task_cpu(p),
1181 .src_nid = task_node(p),
1182
1183 .imbalance_pct = 112,
1184
1185 .best_task = NULL,
1186 .best_imp = 0,
1187 .best_cpu = -1
1188 };
1189 struct sched_domain *sd;
1190 unsigned long taskweight, groupweight;
1191 int nid, ret;
1192 long taskimp, groupimp;
1193
1194 /*
1195 * Pick the lowest SD_NUMA domain, as that would have the smallest
1196 * imbalance and would be the first to start moving tasks about.
1197 *
1198 * And we want to avoid any moving of tasks about, as that would create
1199 * random movement of tasks -- counter the numa conditions we're trying
1200 * to satisfy here.
1201 */
1202 rcu_read_lock();
1203 sd = rcu_dereference(per_cpu(sd_numa, env.src_cpu));
1204 env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2;
1205 rcu_read_unlock();
1206
1207 taskweight = task_weight(p, env.src_nid);
1208 groupweight = group_weight(p, env.src_nid);
1209 update_numa_stats(&env.src_stats, env.src_nid);
1210 env.dst_nid = p->numa_preferred_nid;
1211 taskimp = task_weight(p, env.dst_nid) - taskweight;
1212 groupimp = group_weight(p, env.dst_nid) - groupweight;
1213 update_numa_stats(&env.dst_stats, env.dst_nid);
1214
1215 /* If the preferred nid has capacity, try to use it. */
1216 if (env.dst_stats.has_capacity)
1217 task_numa_find_cpu(&env, taskimp, groupimp);
1218
1219 /* No space available on the preferred nid. Look elsewhere. */
1220 if (env.best_cpu == -1) {
1221 for_each_online_node(nid) {
1222 if (nid == env.src_nid || nid == p->numa_preferred_nid)
1223 continue;
1224
1225 /* Only consider nodes where both task and groups benefit */
1226 taskimp = task_weight(p, nid) - taskweight;
1227 groupimp = group_weight(p, nid) - groupweight;
1228 if (taskimp < 0 && groupimp < 0)
1229 continue;
1230
1231 env.dst_nid = nid;
1232 update_numa_stats(&env.dst_stats, env.dst_nid);
1233 task_numa_find_cpu(&env, taskimp, groupimp);
1234 }
1235 }
1236
1237 /* No better CPU than the current one was found. */
1238 if (env.best_cpu == -1)
1239 return -EAGAIN;
1240
1241 sched_setnuma(p, env.dst_nid);
1242
1243 /*
1244 * Reset the scan period if the task is being rescheduled on an
1245 * alternative node to recheck if the tasks is now properly placed.
1246 */
1247 p->numa_scan_period = task_scan_min(p);
1248
1249 if (env.best_task == NULL) {
1250 int ret = migrate_task_to(p, env.best_cpu);
1251 return ret;
1252 }
1253
1254 ret = migrate_swap(p, env.best_task);
1255 put_task_struct(env.best_task);
1256 return ret;
1257}
1258
1259/* Attempt to migrate a task to a CPU on the preferred node. */
1260static void numa_migrate_preferred(struct task_struct *p)
1261{
1262 /* This task has no NUMA fault statistics yet */
1263 if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
1264 return;
1265
1266 /* Periodically retry migrating the task to the preferred node */
1267 p->numa_migrate_retry = jiffies + HZ;
1268
1269 /* Success if task is already running on preferred CPU */
1270 if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid)
838 return; 1271 return;
1272
1273 /* Otherwise, try migrate to a CPU on the preferred node */
1274 task_numa_migrate(p);
1275}
1276
1277/*
1278 * When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS
1279 * increments. The more local the fault statistics are, the higher the scan
1280 * period will be for the next scan window. If local/remote ratio is below
1281 * NUMA_PERIOD_THRESHOLD (where range of ratio is 1..NUMA_PERIOD_SLOTS) the
1282 * scan period will decrease
1283 */
1284#define NUMA_PERIOD_SLOTS 10
1285#define NUMA_PERIOD_THRESHOLD 3
1286
1287/*
1288 * Increase the scan period (slow down scanning) if the majority of
1289 * our memory is already on our local node, or if the majority of
1290 * the page accesses are shared with other processes.
1291 * Otherwise, decrease the scan period.
1292 */
1293static void update_task_scan_period(struct task_struct *p,
1294 unsigned long shared, unsigned long private)
1295{
1296 unsigned int period_slot;
1297 int ratio;
1298 int diff;
1299
1300 unsigned long remote = p->numa_faults_locality[0];
1301 unsigned long local = p->numa_faults_locality[1];
1302
1303 /*
1304 * If there were no record hinting faults then either the task is
1305 * completely idle or all activity is areas that are not of interest
1306 * to automatic numa balancing. Scan slower
1307 */
1308 if (local + shared == 0) {
1309 p->numa_scan_period = min(p->numa_scan_period_max,
1310 p->numa_scan_period << 1);
1311
1312 p->mm->numa_next_scan = jiffies +
1313 msecs_to_jiffies(p->numa_scan_period);
1314
1315 return;
1316 }
1317
1318 /*
1319 * Prepare to scale scan period relative to the current period.
1320 * == NUMA_PERIOD_THRESHOLD scan period stays the same
1321 * < NUMA_PERIOD_THRESHOLD scan period decreases (scan faster)
1322 * >= NUMA_PERIOD_THRESHOLD scan period increases (scan slower)
1323 */
1324 period_slot = DIV_ROUND_UP(p->numa_scan_period, NUMA_PERIOD_SLOTS);
1325 ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote);
1326 if (ratio >= NUMA_PERIOD_THRESHOLD) {
1327 int slot = ratio - NUMA_PERIOD_THRESHOLD;
1328 if (!slot)
1329 slot = 1;
1330 diff = slot * period_slot;
1331 } else {
1332 diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot;
1333
1334 /*
1335 * Scale scan rate increases based on sharing. There is an
1336 * inverse relationship between the degree of sharing and
1337 * the adjustment made to the scanning period. Broadly
1338 * speaking the intent is that there is little point
1339 * scanning faster if shared accesses dominate as it may
1340 * simply bounce migrations uselessly
1341 */
1342 period_slot = DIV_ROUND_UP(diff, NUMA_PERIOD_SLOTS);
1343 ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared));
1344 diff = (diff * ratio) / NUMA_PERIOD_SLOTS;
1345 }
1346
1347 p->numa_scan_period = clamp(p->numa_scan_period + diff,
1348 task_scan_min(p), task_scan_max(p));
1349 memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
1350}
1351
1352static void task_numa_placement(struct task_struct *p)
1353{
1354 int seq, nid, max_nid = -1, max_group_nid = -1;
1355 unsigned long max_faults = 0, max_group_faults = 0;
1356 unsigned long fault_types[2] = { 0, 0 };
1357 spinlock_t *group_lock = NULL;
1358
839 seq = ACCESS_ONCE(p->mm->numa_scan_seq); 1359 seq = ACCESS_ONCE(p->mm->numa_scan_seq);
840 if (p->numa_scan_seq == seq) 1360 if (p->numa_scan_seq == seq)
841 return; 1361 return;
842 p->numa_scan_seq = seq; 1362 p->numa_scan_seq = seq;
1363 p->numa_scan_period_max = task_scan_max(p);
1364
1365 /* If the task is part of a group prevent parallel updates to group stats */
1366 if (p->numa_group) {
1367 group_lock = &p->numa_group->lock;
1368 spin_lock(group_lock);
1369 }
1370
1371 /* Find the node with the highest number of faults */
1372 for_each_online_node(nid) {
1373 unsigned long faults = 0, group_faults = 0;
1374 int priv, i;
1375
1376 for (priv = 0; priv < 2; priv++) {
1377 long diff;
1378
1379 i = task_faults_idx(nid, priv);
1380 diff = -p->numa_faults[i];
1381
1382 /* Decay existing window, copy faults since last scan */
1383 p->numa_faults[i] >>= 1;
1384 p->numa_faults[i] += p->numa_faults_buffer[i];
1385 fault_types[priv] += p->numa_faults_buffer[i];
1386 p->numa_faults_buffer[i] = 0;
1387
1388 faults += p->numa_faults[i];
1389 diff += p->numa_faults[i];
1390 p->total_numa_faults += diff;
1391 if (p->numa_group) {
1392 /* safe because we can only change our own group */
1393 p->numa_group->faults[i] += diff;
1394 p->numa_group->total_faults += diff;
1395 group_faults += p->numa_group->faults[i];
1396 }
1397 }
1398
1399 if (faults > max_faults) {
1400 max_faults = faults;
1401 max_nid = nid;
1402 }
1403
1404 if (group_faults > max_group_faults) {
1405 max_group_faults = group_faults;
1406 max_group_nid = nid;
1407 }
1408 }
1409
1410 update_task_scan_period(p, fault_types[0], fault_types[1]);
1411
1412 if (p->numa_group) {
1413 /*
1414 * If the preferred task and group nids are different,
1415 * iterate over the nodes again to find the best place.
1416 */
1417 if (max_nid != max_group_nid) {
1418 unsigned long weight, max_weight = 0;
1419
1420 for_each_online_node(nid) {
1421 weight = task_weight(p, nid) + group_weight(p, nid);
1422 if (weight > max_weight) {
1423 max_weight = weight;
1424 max_nid = nid;
1425 }
1426 }
1427 }
1428
1429 spin_unlock(group_lock);
1430 }
1431
1432 /* Preferred node as the node with the most faults */
1433 if (max_faults && max_nid != p->numa_preferred_nid) {
1434 /* Update the preferred nid and migrate task if possible */
1435 sched_setnuma(p, max_nid);
1436 numa_migrate_preferred(p);
1437 }
1438}
1439
1440static inline int get_numa_group(struct numa_group *grp)
1441{
1442 return atomic_inc_not_zero(&grp->refcount);
1443}
1444
1445static inline void put_numa_group(struct numa_group *grp)
1446{
1447 if (atomic_dec_and_test(&grp->refcount))
1448 kfree_rcu(grp, rcu);
1449}
1450
1451static void task_numa_group(struct task_struct *p, int cpupid, int flags,
1452 int *priv)
1453{
1454 struct numa_group *grp, *my_grp;
1455 struct task_struct *tsk;
1456 bool join = false;
1457 int cpu = cpupid_to_cpu(cpupid);
1458 int i;
1459
1460 if (unlikely(!p->numa_group)) {
1461 unsigned int size = sizeof(struct numa_group) +
1462 2*nr_node_ids*sizeof(unsigned long);
1463
1464 grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
1465 if (!grp)
1466 return;
1467
1468 atomic_set(&grp->refcount, 1);
1469 spin_lock_init(&grp->lock);
1470 INIT_LIST_HEAD(&grp->task_list);
1471 grp->gid = p->pid;
1472
1473 for (i = 0; i < 2*nr_node_ids; i++)
1474 grp->faults[i] = p->numa_faults[i];
1475
1476 grp->total_faults = p->total_numa_faults;
1477
1478 list_add(&p->numa_entry, &grp->task_list);
1479 grp->nr_tasks++;
1480 rcu_assign_pointer(p->numa_group, grp);
1481 }
1482
1483 rcu_read_lock();
1484 tsk = ACCESS_ONCE(cpu_rq(cpu)->curr);
1485
1486 if (!cpupid_match_pid(tsk, cpupid))
1487 goto no_join;
1488
1489 grp = rcu_dereference(tsk->numa_group);
1490 if (!grp)
1491 goto no_join;
1492
1493 my_grp = p->numa_group;
1494 if (grp == my_grp)
1495 goto no_join;
1496
1497 /*
1498 * Only join the other group if its bigger; if we're the bigger group,
1499 * the other task will join us.
1500 */
1501 if (my_grp->nr_tasks > grp->nr_tasks)
1502 goto no_join;
1503
1504 /*
1505 * Tie-break on the grp address.
1506 */
1507 if (my_grp->nr_tasks == grp->nr_tasks && my_grp > grp)
1508 goto no_join;
1509
1510 /* Always join threads in the same process. */
1511 if (tsk->mm == current->mm)
1512 join = true;
1513
1514 /* Simple filter to avoid false positives due to PID collisions */
1515 if (flags & TNF_SHARED)
1516 join = true;
1517
1518 /* Update priv based on whether false sharing was detected */
1519 *priv = !join;
1520
1521 if (join && !get_numa_group(grp))
1522 goto no_join;
843 1523
844 /* FIXME: Scheduling placement policy hints go here */ 1524 rcu_read_unlock();
1525
1526 if (!join)
1527 return;
1528
1529 double_lock(&my_grp->lock, &grp->lock);
1530
1531 for (i = 0; i < 2*nr_node_ids; i++) {
1532 my_grp->faults[i] -= p->numa_faults[i];
1533 grp->faults[i] += p->numa_faults[i];
1534 }
1535 my_grp->total_faults -= p->total_numa_faults;
1536 grp->total_faults += p->total_numa_faults;
1537
1538 list_move(&p->numa_entry, &grp->task_list);
1539 my_grp->nr_tasks--;
1540 grp->nr_tasks++;
1541
1542 spin_unlock(&my_grp->lock);
1543 spin_unlock(&grp->lock);
1544
1545 rcu_assign_pointer(p->numa_group, grp);
1546
1547 put_numa_group(my_grp);
1548 return;
1549
1550no_join:
1551 rcu_read_unlock();
1552 return;
1553}
1554
1555void task_numa_free(struct task_struct *p)
1556{
1557 struct numa_group *grp = p->numa_group;
1558 int i;
1559 void *numa_faults = p->numa_faults;
1560
1561 if (grp) {
1562 spin_lock(&grp->lock);
1563 for (i = 0; i < 2*nr_node_ids; i++)
1564 grp->faults[i] -= p->numa_faults[i];
1565 grp->total_faults -= p->total_numa_faults;
1566
1567 list_del(&p->numa_entry);
1568 grp->nr_tasks--;
1569 spin_unlock(&grp->lock);
1570 rcu_assign_pointer(p->numa_group, NULL);
1571 put_numa_group(grp);
1572 }
1573
1574 p->numa_faults = NULL;
1575 p->numa_faults_buffer = NULL;
1576 kfree(numa_faults);
845} 1577}
846 1578
847/* 1579/*
848 * Got a PROT_NONE fault for a page on @node. 1580 * Got a PROT_NONE fault for a page on @node.
849 */ 1581 */
850void task_numa_fault(int node, int pages, bool migrated) 1582void task_numa_fault(int last_cpupid, int node, int pages, int flags)
851{ 1583{
852 struct task_struct *p = current; 1584 struct task_struct *p = current;
1585 bool migrated = flags & TNF_MIGRATED;
1586 int priv;
853 1587
854 if (!numabalancing_enabled) 1588 if (!numabalancing_enabled)
855 return; 1589 return;
856 1590
857 /* FIXME: Allocate task-specific structure for placement policy here */ 1591 /* for example, ksmd faulting in a user's mm */
1592 if (!p->mm)
1593 return;
1594
1595 /* Do not worry about placement if exiting */
1596 if (p->state == TASK_DEAD)
1597 return;
1598
1599 /* Allocate buffer to track faults on a per-node basis */
1600 if (unlikely(!p->numa_faults)) {
1601 int size = sizeof(*p->numa_faults) * 2 * nr_node_ids;
1602
1603 /* numa_faults and numa_faults_buffer share the allocation */
1604 p->numa_faults = kzalloc(size * 2, GFP_KERNEL|__GFP_NOWARN);
1605 if (!p->numa_faults)
1606 return;
1607
1608 BUG_ON(p->numa_faults_buffer);
1609 p->numa_faults_buffer = p->numa_faults + (2 * nr_node_ids);
1610 p->total_numa_faults = 0;
1611 memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
1612 }
858 1613
859 /* 1614 /*
860 * If pages are properly placed (did not migrate) then scan slower. 1615 * First accesses are treated as private, otherwise consider accesses
861 * This is reset periodically in case of phase changes 1616 * to be private if the accessing pid has not changed
862 */ 1617 */
863 if (!migrated) 1618 if (unlikely(last_cpupid == (-1 & LAST_CPUPID_MASK))) {
864 p->numa_scan_period = min(sysctl_numa_balancing_scan_period_max, 1619 priv = 1;
865 p->numa_scan_period + jiffies_to_msecs(10)); 1620 } else {
1621 priv = cpupid_match_pid(p, last_cpupid);
1622 if (!priv && !(flags & TNF_NO_GROUP))
1623 task_numa_group(p, last_cpupid, flags, &priv);
1624 }
866 1625
867 task_numa_placement(p); 1626 task_numa_placement(p);
1627
1628 /*
1629 * Retry task to preferred node migration periodically, in case it
1630 * case it previously failed, or the scheduler moved us.
1631 */
1632 if (time_after(jiffies, p->numa_migrate_retry))
1633 numa_migrate_preferred(p);
1634
1635 if (migrated)
1636 p->numa_pages_migrated += pages;
1637
1638 p->numa_faults_buffer[task_faults_idx(node, priv)] += pages;
1639 p->numa_faults_locality[!!(flags & TNF_FAULT_LOCAL)] += pages;
868} 1640}
869 1641
870static void reset_ptenuma_scan(struct task_struct *p) 1642static void reset_ptenuma_scan(struct task_struct *p)
@@ -884,6 +1656,7 @@ void task_numa_work(struct callback_head *work)
884 struct mm_struct *mm = p->mm; 1656 struct mm_struct *mm = p->mm;
885 struct vm_area_struct *vma; 1657 struct vm_area_struct *vma;
886 unsigned long start, end; 1658 unsigned long start, end;
1659 unsigned long nr_pte_updates = 0;
887 long pages; 1660 long pages;
888 1661
889 WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work)); 1662 WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work));
@@ -900,35 +1673,9 @@ void task_numa_work(struct callback_head *work)
900 if (p->flags & PF_EXITING) 1673 if (p->flags & PF_EXITING)
901 return; 1674 return;
902 1675
903 /* 1676 if (!mm->numa_next_scan) {
904 * We do not care about task placement until a task runs on a node 1677 mm->numa_next_scan = now +
905 * other than the first one used by the address space. This is 1678 msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
906 * largely because migrations are driven by what CPU the task
907 * is running on. If it's never scheduled on another node, it'll
908 * not migrate so why bother trapping the fault.
909 */
910 if (mm->first_nid == NUMA_PTE_SCAN_INIT)
911 mm->first_nid = numa_node_id();
912 if (mm->first_nid != NUMA_PTE_SCAN_ACTIVE) {
913 /* Are we running on a new node yet? */
914 if (numa_node_id() == mm->first_nid &&
915 !sched_feat_numa(NUMA_FORCE))
916 return;
917
918 mm->first_nid = NUMA_PTE_SCAN_ACTIVE;
919 }
920
921 /*
922 * Reset the scan period if enough time has gone by. Objective is that
923 * scanning will be reduced if pages are properly placed. As tasks
924 * can enter different phases this needs to be re-examined. Lacking
925 * proper tracking of reference behaviour, this blunt hammer is used.
926 */
927 migrate = mm->numa_next_reset;
928 if (time_after(now, migrate)) {
929 p->numa_scan_period = sysctl_numa_balancing_scan_period_min;
930 next_scan = now + msecs_to_jiffies(sysctl_numa_balancing_scan_period_reset);
931 xchg(&mm->numa_next_reset, next_scan);
932 } 1679 }
933 1680
934 /* 1681 /*
@@ -938,20 +1685,20 @@ void task_numa_work(struct callback_head *work)
938 if (time_before(now, migrate)) 1685 if (time_before(now, migrate))
939 return; 1686 return;
940 1687
941 if (p->numa_scan_period == 0) 1688 if (p->numa_scan_period == 0) {
942 p->numa_scan_period = sysctl_numa_balancing_scan_period_min; 1689 p->numa_scan_period_max = task_scan_max(p);
1690 p->numa_scan_period = task_scan_min(p);
1691 }
943 1692
944 next_scan = now + msecs_to_jiffies(p->numa_scan_period); 1693 next_scan = now + msecs_to_jiffies(p->numa_scan_period);
945 if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate) 1694 if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate)
946 return; 1695 return;
947 1696
948 /* 1697 /*
949 * Do not set pte_numa if the current running node is rate-limited. 1698 * Delay this task enough that another task of this mm will likely win
950 * This loses statistics on the fault but if we are unwilling to 1699 * the next time around.
951 * migrate to this node, it is less likely we can do useful work
952 */ 1700 */
953 if (migrate_ratelimited(numa_node_id())) 1701 p->node_stamp += 2 * TICK_NSEC;
954 return;
955 1702
956 start = mm->numa_scan_offset; 1703 start = mm->numa_scan_offset;
957 pages = sysctl_numa_balancing_scan_size; 1704 pages = sysctl_numa_balancing_scan_size;
@@ -967,18 +1714,32 @@ void task_numa_work(struct callback_head *work)
967 vma = mm->mmap; 1714 vma = mm->mmap;
968 } 1715 }
969 for (; vma; vma = vma->vm_next) { 1716 for (; vma; vma = vma->vm_next) {
970 if (!vma_migratable(vma)) 1717 if (!vma_migratable(vma) || !vma_policy_mof(p, vma))
971 continue; 1718 continue;
972 1719
973 /* Skip small VMAs. They are not likely to be of relevance */ 1720 /*
974 if (vma->vm_end - vma->vm_start < HPAGE_SIZE) 1721 * Shared library pages mapped by multiple processes are not
1722 * migrated as it is expected they are cache replicated. Avoid
1723 * hinting faults in read-only file-backed mappings or the vdso
1724 * as migrating the pages will be of marginal benefit.
1725 */
1726 if (!vma->vm_mm ||
1727 (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ)))
975 continue; 1728 continue;
976 1729
977 do { 1730 do {
978 start = max(start, vma->vm_start); 1731 start = max(start, vma->vm_start);
979 end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); 1732 end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);
980 end = min(end, vma->vm_end); 1733 end = min(end, vma->vm_end);
981 pages -= change_prot_numa(vma, start, end); 1734 nr_pte_updates += change_prot_numa(vma, start, end);
1735
1736 /*
1737 * Scan sysctl_numa_balancing_scan_size but ensure that
1738 * at least one PTE is updated so that unused virtual
1739 * address space is quickly skipped.
1740 */
1741 if (nr_pte_updates)
1742 pages -= (end - start) >> PAGE_SHIFT;
982 1743
983 start = end; 1744 start = end;
984 if (pages <= 0) 1745 if (pages <= 0)
@@ -988,10 +1749,10 @@ void task_numa_work(struct callback_head *work)
988 1749
989out: 1750out:
990 /* 1751 /*
991 * It is possible to reach the end of the VMA list but the last few VMAs are 1752 * It is possible to reach the end of the VMA list but the last few
992 * not guaranteed to the vma_migratable. If they are not, we would find the 1753 * VMAs are not guaranteed to the vma_migratable. If they are not, we
993 * !migratable VMA on the next scan but not reset the scanner to the start 1754 * would find the !migratable VMA on the next scan but not reset the
994 * so check it now. 1755 * scanner to the start so check it now.
995 */ 1756 */
996 if (vma) 1757 if (vma)
997 mm->numa_scan_offset = start; 1758 mm->numa_scan_offset = start;
@@ -1025,8 +1786,8 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
1025 1786
1026 if (now - curr->node_stamp > period) { 1787 if (now - curr->node_stamp > period) {
1027 if (!curr->node_stamp) 1788 if (!curr->node_stamp)
1028 curr->numa_scan_period = sysctl_numa_balancing_scan_period_min; 1789 curr->numa_scan_period = task_scan_min(curr);
1029 curr->node_stamp = now; 1790 curr->node_stamp += period;
1030 1791
1031 if (!time_before(jiffies, curr->mm->numa_next_scan)) { 1792 if (!time_before(jiffies, curr->mm->numa_next_scan)) {
1032 init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */ 1793 init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */
@@ -1038,6 +1799,14 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
1038static void task_tick_numa(struct rq *rq, struct task_struct *curr) 1799static void task_tick_numa(struct rq *rq, struct task_struct *curr)
1039{ 1800{
1040} 1801}
1802
1803static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p)
1804{
1805}
1806
1807static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
1808{
1809}
1041#endif /* CONFIG_NUMA_BALANCING */ 1810#endif /* CONFIG_NUMA_BALANCING */
1042 1811
1043static void 1812static void
@@ -1047,8 +1816,12 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
1047 if (!parent_entity(se)) 1816 if (!parent_entity(se))
1048 update_load_add(&rq_of(cfs_rq)->load, se->load.weight); 1817 update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
1049#ifdef CONFIG_SMP 1818#ifdef CONFIG_SMP
1050 if (entity_is_task(se)) 1819 if (entity_is_task(se)) {
1051 list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks); 1820 struct rq *rq = rq_of(cfs_rq);
1821
1822 account_numa_enqueue(rq, task_of(se));
1823 list_add(&se->group_node, &rq->cfs_tasks);
1824 }
1052#endif 1825#endif
1053 cfs_rq->nr_running++; 1826 cfs_rq->nr_running++;
1054} 1827}
@@ -1059,8 +1832,10 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
1059 update_load_sub(&cfs_rq->load, se->load.weight); 1832 update_load_sub(&cfs_rq->load, se->load.weight);
1060 if (!parent_entity(se)) 1833 if (!parent_entity(se))
1061 update_load_sub(&rq_of(cfs_rq)->load, se->load.weight); 1834 update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
1062 if (entity_is_task(se)) 1835 if (entity_is_task(se)) {
1836 account_numa_dequeue(rq_of(cfs_rq), task_of(se));
1063 list_del_init(&se->group_node); 1837 list_del_init(&se->group_node);
1838 }
1064 cfs_rq->nr_running--; 1839 cfs_rq->nr_running--;
1065} 1840}
1066 1841
@@ -2070,13 +2845,14 @@ static inline bool cfs_bandwidth_used(void)
2070 return static_key_false(&__cfs_bandwidth_used); 2845 return static_key_false(&__cfs_bandwidth_used);
2071} 2846}
2072 2847
2073void account_cfs_bandwidth_used(int enabled, int was_enabled) 2848void cfs_bandwidth_usage_inc(void)
2849{
2850 static_key_slow_inc(&__cfs_bandwidth_used);
2851}
2852
2853void cfs_bandwidth_usage_dec(void)
2074{ 2854{
2075 /* only need to count groups transitioning between enabled/!enabled */ 2855 static_key_slow_dec(&__cfs_bandwidth_used);
2076 if (enabled && !was_enabled)
2077 static_key_slow_inc(&__cfs_bandwidth_used);
2078 else if (!enabled && was_enabled)
2079 static_key_slow_dec(&__cfs_bandwidth_used);
2080} 2856}
2081#else /* HAVE_JUMP_LABEL */ 2857#else /* HAVE_JUMP_LABEL */
2082static bool cfs_bandwidth_used(void) 2858static bool cfs_bandwidth_used(void)
@@ -2084,7 +2860,8 @@ static bool cfs_bandwidth_used(void)
2084 return true; 2860 return true;
2085} 2861}
2086 2862
2087void account_cfs_bandwidth_used(int enabled, int was_enabled) {} 2863void cfs_bandwidth_usage_inc(void) {}
2864void cfs_bandwidth_usage_dec(void) {}
2088#endif /* HAVE_JUMP_LABEL */ 2865#endif /* HAVE_JUMP_LABEL */
2089 2866
2090/* 2867/*
@@ -2335,6 +3112,8 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
2335 cfs_rq->throttled_clock = rq_clock(rq); 3112 cfs_rq->throttled_clock = rq_clock(rq);
2336 raw_spin_lock(&cfs_b->lock); 3113 raw_spin_lock(&cfs_b->lock);
2337 list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); 3114 list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
3115 if (!cfs_b->timer_active)
3116 __start_cfs_bandwidth(cfs_b);
2338 raw_spin_unlock(&cfs_b->lock); 3117 raw_spin_unlock(&cfs_b->lock);
2339} 3118}
2340 3119
@@ -2448,6 +3227,13 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
2448 if (idle) 3227 if (idle)
2449 goto out_unlock; 3228 goto out_unlock;
2450 3229
3230 /*
3231 * if we have relooped after returning idle once, we need to update our
3232 * status as actually running, so that other cpus doing
3233 * __start_cfs_bandwidth will stop trying to cancel us.
3234 */
3235 cfs_b->timer_active = 1;
3236
2451 __refill_cfs_bandwidth_runtime(cfs_b); 3237 __refill_cfs_bandwidth_runtime(cfs_b);
2452 3238
2453 if (!throttled) { 3239 if (!throttled) {
@@ -2508,7 +3294,13 @@ static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC;
2508/* how long we wait to gather additional slack before distributing */ 3294/* how long we wait to gather additional slack before distributing */
2509static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC; 3295static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC;
2510 3296
2511/* are we near the end of the current quota period? */ 3297/*
3298 * Are we near the end of the current quota period?
3299 *
3300 * Requires cfs_b->lock for hrtimer_expires_remaining to be safe against the
3301 * hrtimer base being cleared by __hrtimer_start_range_ns. In the case of
3302 * migrate_hrtimers, base is never cleared, so we are fine.
3303 */
2512static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire) 3304static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
2513{ 3305{
2514 struct hrtimer *refresh_timer = &cfs_b->period_timer; 3306 struct hrtimer *refresh_timer = &cfs_b->period_timer;
@@ -2584,10 +3376,12 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
2584 u64 expires; 3376 u64 expires;
2585 3377
2586 /* confirm we're still not at a refresh boundary */ 3378 /* confirm we're still not at a refresh boundary */
2587 if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) 3379 raw_spin_lock(&cfs_b->lock);
3380 if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) {
3381 raw_spin_unlock(&cfs_b->lock);
2588 return; 3382 return;
3383 }
2589 3384
2590 raw_spin_lock(&cfs_b->lock);
2591 if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) { 3385 if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) {
2592 runtime = cfs_b->runtime; 3386 runtime = cfs_b->runtime;
2593 cfs_b->runtime = 0; 3387 cfs_b->runtime = 0;
@@ -2708,11 +3502,11 @@ void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
2708 * (timer_active==0 becomes visible before the hrtimer call-back 3502 * (timer_active==0 becomes visible before the hrtimer call-back
2709 * terminates). In either case we ensure that it's re-programmed 3503 * terminates). In either case we ensure that it's re-programmed
2710 */ 3504 */
2711 while (unlikely(hrtimer_active(&cfs_b->period_timer))) { 3505 while (unlikely(hrtimer_active(&cfs_b->period_timer)) &&
3506 hrtimer_try_to_cancel(&cfs_b->period_timer) < 0) {
3507 /* bounce the lock to allow do_sched_cfs_period_timer to run */
2712 raw_spin_unlock(&cfs_b->lock); 3508 raw_spin_unlock(&cfs_b->lock);
2713 /* ensure cfs_b->lock is available while we wait */ 3509 cpu_relax();
2714 hrtimer_cancel(&cfs_b->period_timer);
2715
2716 raw_spin_lock(&cfs_b->lock); 3510 raw_spin_lock(&cfs_b->lock);
2717 /* if someone else restarted the timer then we're done */ 3511 /* if someone else restarted the timer then we're done */
2718 if (cfs_b->timer_active) 3512 if (cfs_b->timer_active)
@@ -3113,7 +3907,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
3113{ 3907{
3114 struct sched_entity *se = tg->se[cpu]; 3908 struct sched_entity *se = tg->se[cpu];
3115 3909
3116 if (!tg->parent) /* the trivial, non-cgroup case */ 3910 if (!tg->parent || !wl) /* the trivial, non-cgroup case */
3117 return wl; 3911 return wl;
3118 3912
3119 for_each_sched_entity(se) { 3913 for_each_sched_entity(se) {
@@ -3166,8 +3960,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
3166} 3960}
3167#else 3961#else
3168 3962
3169static inline unsigned long effective_load(struct task_group *tg, int cpu, 3963static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
3170 unsigned long wl, unsigned long wg)
3171{ 3964{
3172 return wl; 3965 return wl;
3173} 3966}
@@ -3420,11 +4213,10 @@ done:
3420 * preempt must be disabled. 4213 * preempt must be disabled.
3421 */ 4214 */
3422static int 4215static int
3423select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) 4216select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_flags)
3424{ 4217{
3425 struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; 4218 struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
3426 int cpu = smp_processor_id(); 4219 int cpu = smp_processor_id();
3427 int prev_cpu = task_cpu(p);
3428 int new_cpu = cpu; 4220 int new_cpu = cpu;
3429 int want_affine = 0; 4221 int want_affine = 0;
3430 int sync = wake_flags & WF_SYNC; 4222 int sync = wake_flags & WF_SYNC;
@@ -3904,9 +4696,12 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
3904 4696
3905static unsigned long __read_mostly max_load_balance_interval = HZ/10; 4697static unsigned long __read_mostly max_load_balance_interval = HZ/10;
3906 4698
4699enum fbq_type { regular, remote, all };
4700
3907#define LBF_ALL_PINNED 0x01 4701#define LBF_ALL_PINNED 0x01
3908#define LBF_NEED_BREAK 0x02 4702#define LBF_NEED_BREAK 0x02
3909#define LBF_SOME_PINNED 0x04 4703#define LBF_DST_PINNED 0x04
4704#define LBF_SOME_PINNED 0x08
3910 4705
3911struct lb_env { 4706struct lb_env {
3912 struct sched_domain *sd; 4707 struct sched_domain *sd;
@@ -3929,6 +4724,8 @@ struct lb_env {
3929 unsigned int loop; 4724 unsigned int loop;
3930 unsigned int loop_break; 4725 unsigned int loop_break;
3931 unsigned int loop_max; 4726 unsigned int loop_max;
4727
4728 enum fbq_type fbq_type;
3932}; 4729};
3933 4730
3934/* 4731/*
@@ -3975,6 +4772,78 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
3975 return delta < (s64)sysctl_sched_migration_cost; 4772 return delta < (s64)sysctl_sched_migration_cost;
3976} 4773}
3977 4774
4775#ifdef CONFIG_NUMA_BALANCING
4776/* Returns true if the destination node has incurred more faults */
4777static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env)
4778{
4779 int src_nid, dst_nid;
4780
4781 if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults ||
4782 !(env->sd->flags & SD_NUMA)) {
4783 return false;
4784 }
4785
4786 src_nid = cpu_to_node(env->src_cpu);
4787 dst_nid = cpu_to_node(env->dst_cpu);
4788
4789 if (src_nid == dst_nid)
4790 return false;
4791
4792 /* Always encourage migration to the preferred node. */
4793 if (dst_nid == p->numa_preferred_nid)
4794 return true;
4795
4796 /* If both task and group weight improve, this move is a winner. */
4797 if (task_weight(p, dst_nid) > task_weight(p, src_nid) &&
4798 group_weight(p, dst_nid) > group_weight(p, src_nid))
4799 return true;
4800
4801 return false;
4802}
4803
4804
4805static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
4806{
4807 int src_nid, dst_nid;
4808
4809 if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
4810 return false;
4811
4812 if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
4813 return false;
4814
4815 src_nid = cpu_to_node(env->src_cpu);
4816 dst_nid = cpu_to_node(env->dst_cpu);
4817
4818 if (src_nid == dst_nid)
4819 return false;
4820
4821 /* Migrating away from the preferred node is always bad. */
4822 if (src_nid == p->numa_preferred_nid)
4823 return true;
4824
4825 /* If either task or group weight get worse, don't do it. */
4826 if (task_weight(p, dst_nid) < task_weight(p, src_nid) ||
4827 group_weight(p, dst_nid) < group_weight(p, src_nid))
4828 return true;
4829
4830 return false;
4831}
4832
4833#else
4834static inline bool migrate_improves_locality(struct task_struct *p,
4835 struct lb_env *env)
4836{
4837 return false;
4838}
4839
4840static inline bool migrate_degrades_locality(struct task_struct *p,
4841 struct lb_env *env)
4842{
4843 return false;
4844}
4845#endif
4846
3978/* 4847/*
3979 * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? 4848 * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
3980 */ 4849 */
@@ -3997,6 +4866,8 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
3997 4866
3998 schedstat_inc(p, se.statistics.nr_failed_migrations_affine); 4867 schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
3999 4868
4869 env->flags |= LBF_SOME_PINNED;
4870
4000 /* 4871 /*
4001 * Remember if this task can be migrated to any other cpu in 4872 * Remember if this task can be migrated to any other cpu in
4002 * our sched_group. We may want to revisit it if we couldn't 4873 * our sched_group. We may want to revisit it if we couldn't
@@ -4005,13 +4876,13 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
4005 * Also avoid computing new_dst_cpu if we have already computed 4876 * Also avoid computing new_dst_cpu if we have already computed
4006 * one in current iteration. 4877 * one in current iteration.
4007 */ 4878 */
4008 if (!env->dst_grpmask || (env->flags & LBF_SOME_PINNED)) 4879 if (!env->dst_grpmask || (env->flags & LBF_DST_PINNED))
4009 return 0; 4880 return 0;
4010 4881
4011 /* Prevent to re-select dst_cpu via env's cpus */ 4882 /* Prevent to re-select dst_cpu via env's cpus */
4012 for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) { 4883 for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
4013 if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) { 4884 if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) {
4014 env->flags |= LBF_SOME_PINNED; 4885 env->flags |= LBF_DST_PINNED;
4015 env->new_dst_cpu = cpu; 4886 env->new_dst_cpu = cpu;
4016 break; 4887 break;
4017 } 4888 }
@@ -4030,11 +4901,24 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
4030 4901
4031 /* 4902 /*
4032 * Aggressive migration if: 4903 * Aggressive migration if:
4033 * 1) task is cache cold, or 4904 * 1) destination numa is preferred
4034 * 2) too many balance attempts have failed. 4905 * 2) task is cache cold, or
4906 * 3) too many balance attempts have failed.
4035 */ 4907 */
4036
4037 tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq), env->sd); 4908 tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq), env->sd);
4909 if (!tsk_cache_hot)
4910 tsk_cache_hot = migrate_degrades_locality(p, env);
4911
4912 if (migrate_improves_locality(p, env)) {
4913#ifdef CONFIG_SCHEDSTATS
4914 if (tsk_cache_hot) {
4915 schedstat_inc(env->sd, lb_hot_gained[env->idle]);
4916 schedstat_inc(p, se.statistics.nr_forced_migrations);
4917 }
4918#endif
4919 return 1;
4920 }
4921
4038 if (!tsk_cache_hot || 4922 if (!tsk_cache_hot ||
4039 env->sd->nr_balance_failed > env->sd->cache_nice_tries) { 4923 env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
4040 4924
@@ -4077,8 +4961,6 @@ static int move_one_task(struct lb_env *env)
4077 return 0; 4961 return 0;
4078} 4962}
4079 4963
4080static unsigned long task_h_load(struct task_struct *p);
4081
4082static const unsigned int sched_nr_migrate_break = 32; 4964static const unsigned int sched_nr_migrate_break = 32;
4083 4965
4084/* 4966/*
@@ -4291,6 +5173,10 @@ struct sg_lb_stats {
4291 unsigned int group_weight; 5173 unsigned int group_weight;
4292 int group_imb; /* Is there an imbalance in the group ? */ 5174 int group_imb; /* Is there an imbalance in the group ? */
4293 int group_has_capacity; /* Is there extra capacity in the group? */ 5175 int group_has_capacity; /* Is there extra capacity in the group? */
5176#ifdef CONFIG_NUMA_BALANCING
5177 unsigned int nr_numa_running;
5178 unsigned int nr_preferred_running;
5179#endif
4294}; 5180};
4295 5181
4296/* 5182/*
@@ -4330,7 +5216,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
4330/** 5216/**
4331 * get_sd_load_idx - Obtain the load index for a given sched domain. 5217 * get_sd_load_idx - Obtain the load index for a given sched domain.
4332 * @sd: The sched_domain whose load_idx is to be obtained. 5218 * @sd: The sched_domain whose load_idx is to be obtained.
4333 * @idle: The Idle status of the CPU for whose sd load_icx is obtained. 5219 * @idle: The idle status of the CPU for whose sd load_idx is obtained.
4334 * 5220 *
4335 * Return: The load index. 5221 * Return: The load index.
4336 */ 5222 */
@@ -4447,7 +5333,7 @@ void update_group_power(struct sched_domain *sd, int cpu)
4447{ 5333{
4448 struct sched_domain *child = sd->child; 5334 struct sched_domain *child = sd->child;
4449 struct sched_group *group, *sdg = sd->groups; 5335 struct sched_group *group, *sdg = sd->groups;
4450 unsigned long power; 5336 unsigned long power, power_orig;
4451 unsigned long interval; 5337 unsigned long interval;
4452 5338
4453 interval = msecs_to_jiffies(sd->balance_interval); 5339 interval = msecs_to_jiffies(sd->balance_interval);
@@ -4459,7 +5345,7 @@ void update_group_power(struct sched_domain *sd, int cpu)
4459 return; 5345 return;
4460 } 5346 }
4461 5347
4462 power = 0; 5348 power_orig = power = 0;
4463 5349
4464 if (child->flags & SD_OVERLAP) { 5350 if (child->flags & SD_OVERLAP) {
4465 /* 5351 /*
@@ -4467,8 +5353,12 @@ void update_group_power(struct sched_domain *sd, int cpu)
4467 * span the current group. 5353 * span the current group.
4468 */ 5354 */
4469 5355
4470 for_each_cpu(cpu, sched_group_cpus(sdg)) 5356 for_each_cpu(cpu, sched_group_cpus(sdg)) {
4471 power += power_of(cpu); 5357 struct sched_group *sg = cpu_rq(cpu)->sd->groups;
5358
5359 power_orig += sg->sgp->power_orig;
5360 power += sg->sgp->power;
5361 }
4472 } else { 5362 } else {
4473 /* 5363 /*
4474 * !SD_OVERLAP domains can assume that child groups 5364 * !SD_OVERLAP domains can assume that child groups
@@ -4477,12 +5367,14 @@ void update_group_power(struct sched_domain *sd, int cpu)
4477 5367
4478 group = child->groups; 5368 group = child->groups;
4479 do { 5369 do {
5370 power_orig += group->sgp->power_orig;
4480 power += group->sgp->power; 5371 power += group->sgp->power;
4481 group = group->next; 5372 group = group->next;
4482 } while (group != child->groups); 5373 } while (group != child->groups);
4483 } 5374 }
4484 5375
4485 sdg->sgp->power_orig = sdg->sgp->power = power; 5376 sdg->sgp->power_orig = power_orig;
5377 sdg->sgp->power = power;
4486} 5378}
4487 5379
4488/* 5380/*
@@ -4526,13 +5418,12 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
4526 * cpu 3 and leave one of the cpus in the second group unused. 5418 * cpu 3 and leave one of the cpus in the second group unused.
4527 * 5419 *
4528 * The current solution to this issue is detecting the skew in the first group 5420 * The current solution to this issue is detecting the skew in the first group
4529 * by noticing it has a cpu that is overloaded while the remaining cpus are 5421 * by noticing the lower domain failed to reach balance and had difficulty
4530 * idle -- or rather, there's a distinct imbalance in the cpus; see 5422 * moving tasks due to affinity constraints.
4531 * sg_imbalanced().
4532 * 5423 *
4533 * When this is so detected; this group becomes a candidate for busiest; see 5424 * When this is so detected; this group becomes a candidate for busiest; see
4534 * update_sd_pick_busiest(). And calculcate_imbalance() and 5425 * update_sd_pick_busiest(). And calculate_imbalance() and
4535 * find_busiest_group() avoid some of the usual balance conditional to allow it 5426 * find_busiest_group() avoid some of the usual balance conditions to allow it
4536 * to create an effective group imbalance. 5427 * to create an effective group imbalance.
4537 * 5428 *
4538 * This is a somewhat tricky proposition since the next run might not find the 5429 * This is a somewhat tricky proposition since the next run might not find the
@@ -4540,49 +5431,36 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
4540 * subtle and fragile situation. 5431 * subtle and fragile situation.
4541 */ 5432 */
4542 5433
4543struct sg_imb_stats { 5434static inline int sg_imbalanced(struct sched_group *group)
4544 unsigned long max_nr_running, min_nr_running;
4545 unsigned long max_cpu_load, min_cpu_load;
4546};
4547
4548static inline void init_sg_imb_stats(struct sg_imb_stats *sgi)
4549{ 5435{
4550 sgi->max_cpu_load = sgi->max_nr_running = 0UL; 5436 return group->sgp->imbalance;
4551 sgi->min_cpu_load = sgi->min_nr_running = ~0UL;
4552} 5437}
4553 5438
4554static inline void 5439/*
4555update_sg_imb_stats(struct sg_imb_stats *sgi, 5440 * Compute the group capacity.
4556 unsigned long load, unsigned long nr_running) 5441 *
5442 * Avoid the issue where N*frac(smt_power) >= 1 creates 'phantom' cores by
5443 * first dividing out the smt factor and computing the actual number of cores
5444 * and limit power unit capacity with that.
5445 */
5446static inline int sg_capacity(struct lb_env *env, struct sched_group *group)
4557{ 5447{
4558 if (load > sgi->max_cpu_load) 5448 unsigned int capacity, smt, cpus;
4559 sgi->max_cpu_load = load; 5449 unsigned int power, power_orig;
4560 if (sgi->min_cpu_load > load)
4561 sgi->min_cpu_load = load;
4562 5450
4563 if (nr_running > sgi->max_nr_running) 5451 power = group->sgp->power;
4564 sgi->max_nr_running = nr_running; 5452 power_orig = group->sgp->power_orig;
4565 if (sgi->min_nr_running > nr_running) 5453 cpus = group->group_weight;
4566 sgi->min_nr_running = nr_running;
4567}
4568 5454
4569static inline int 5455 /* smt := ceil(cpus / power), assumes: 1 < smt_power < 2 */
4570sg_imbalanced(struct sg_lb_stats *sgs, struct sg_imb_stats *sgi) 5456 smt = DIV_ROUND_UP(SCHED_POWER_SCALE * cpus, power_orig);
4571{ 5457 capacity = cpus / smt; /* cores */
4572 /*
4573 * Consider the group unbalanced when the imbalance is larger
4574 * than the average weight of a task.
4575 *
4576 * APZ: with cgroup the avg task weight can vary wildly and
4577 * might not be a suitable number - should we keep a
4578 * normalized nr_running number somewhere that negates
4579 * the hierarchy?
4580 */
4581 if ((sgi->max_cpu_load - sgi->min_cpu_load) >= sgs->load_per_task &&
4582 (sgi->max_nr_running - sgi->min_nr_running) > 1)
4583 return 1;
4584 5458
4585 return 0; 5459 capacity = min_t(unsigned, capacity, DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE));
5460 if (!capacity)
5461 capacity = fix_small_capacity(env->sd, group);
5462
5463 return capacity;
4586} 5464}
4587 5465
4588/** 5466/**
@@ -4597,12 +5475,11 @@ static inline void update_sg_lb_stats(struct lb_env *env,
4597 struct sched_group *group, int load_idx, 5475 struct sched_group *group, int load_idx,
4598 int local_group, struct sg_lb_stats *sgs) 5476 int local_group, struct sg_lb_stats *sgs)
4599{ 5477{
4600 struct sg_imb_stats sgi;
4601 unsigned long nr_running; 5478 unsigned long nr_running;
4602 unsigned long load; 5479 unsigned long load;
4603 int i; 5480 int i;
4604 5481
4605 init_sg_imb_stats(&sgi); 5482 memset(sgs, 0, sizeof(*sgs));
4606 5483
4607 for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { 5484 for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
4608 struct rq *rq = cpu_rq(i); 5485 struct rq *rq = cpu_rq(i);
@@ -4610,24 +5487,22 @@ static inline void update_sg_lb_stats(struct lb_env *env,
4610 nr_running = rq->nr_running; 5487 nr_running = rq->nr_running;
4611 5488
4612 /* Bias balancing toward cpus of our domain */ 5489 /* Bias balancing toward cpus of our domain */
4613 if (local_group) { 5490 if (local_group)
4614 load = target_load(i, load_idx); 5491 load = target_load(i, load_idx);
4615 } else { 5492 else
4616 load = source_load(i, load_idx); 5493 load = source_load(i, load_idx);
4617 update_sg_imb_stats(&sgi, load, nr_running);
4618 }
4619 5494
4620 sgs->group_load += load; 5495 sgs->group_load += load;
4621 sgs->sum_nr_running += nr_running; 5496 sgs->sum_nr_running += nr_running;
5497#ifdef CONFIG_NUMA_BALANCING
5498 sgs->nr_numa_running += rq->nr_numa_running;
5499 sgs->nr_preferred_running += rq->nr_preferred_running;
5500#endif
4622 sgs->sum_weighted_load += weighted_cpuload(i); 5501 sgs->sum_weighted_load += weighted_cpuload(i);
4623 if (idle_cpu(i)) 5502 if (idle_cpu(i))
4624 sgs->idle_cpus++; 5503 sgs->idle_cpus++;
4625 } 5504 }
4626 5505
4627 if (local_group && (env->idle != CPU_NEWLY_IDLE ||
4628 time_after_eq(jiffies, group->sgp->next_update)))
4629 update_group_power(env->sd, env->dst_cpu);
4630
4631 /* Adjust by relative CPU power of the group */ 5506 /* Adjust by relative CPU power of the group */
4632 sgs->group_power = group->sgp->power; 5507 sgs->group_power = group->sgp->power;
4633 sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power; 5508 sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power;
@@ -4635,16 +5510,11 @@ static inline void update_sg_lb_stats(struct lb_env *env,
4635 if (sgs->sum_nr_running) 5510 if (sgs->sum_nr_running)
4636 sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running; 5511 sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
4637 5512
4638 sgs->group_imb = sg_imbalanced(sgs, &sgi);
4639
4640 sgs->group_capacity =
4641 DIV_ROUND_CLOSEST(sgs->group_power, SCHED_POWER_SCALE);
4642
4643 if (!sgs->group_capacity)
4644 sgs->group_capacity = fix_small_capacity(env->sd, group);
4645
4646 sgs->group_weight = group->group_weight; 5513 sgs->group_weight = group->group_weight;
4647 5514
5515 sgs->group_imb = sg_imbalanced(group);
5516 sgs->group_capacity = sg_capacity(env, group);
5517
4648 if (sgs->group_capacity > sgs->sum_nr_running) 5518 if (sgs->group_capacity > sgs->sum_nr_running)
4649 sgs->group_has_capacity = 1; 5519 sgs->group_has_capacity = 1;
4650} 5520}
@@ -4693,14 +5563,42 @@ static bool update_sd_pick_busiest(struct lb_env *env,
4693 return false; 5563 return false;
4694} 5564}
4695 5565
5566#ifdef CONFIG_NUMA_BALANCING
5567static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
5568{
5569 if (sgs->sum_nr_running > sgs->nr_numa_running)
5570 return regular;
5571 if (sgs->sum_nr_running > sgs->nr_preferred_running)
5572 return remote;
5573 return all;
5574}
5575
5576static inline enum fbq_type fbq_classify_rq(struct rq *rq)
5577{
5578 if (rq->nr_running > rq->nr_numa_running)
5579 return regular;
5580 if (rq->nr_running > rq->nr_preferred_running)
5581 return remote;
5582 return all;
5583}
5584#else
5585static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
5586{
5587 return all;
5588}
5589
5590static inline enum fbq_type fbq_classify_rq(struct rq *rq)
5591{
5592 return regular;
5593}
5594#endif /* CONFIG_NUMA_BALANCING */
5595
4696/** 5596/**
4697 * update_sd_lb_stats - Update sched_domain's statistics for load balancing. 5597 * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
4698 * @env: The load balancing environment. 5598 * @env: The load balancing environment.
4699 * @balance: Should we balance.
4700 * @sds: variable to hold the statistics for this sched_domain. 5599 * @sds: variable to hold the statistics for this sched_domain.
4701 */ 5600 */
4702static inline void update_sd_lb_stats(struct lb_env *env, 5601static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds)
4703 struct sd_lb_stats *sds)
4704{ 5602{
4705 struct sched_domain *child = env->sd->child; 5603 struct sched_domain *child = env->sd->child;
4706 struct sched_group *sg = env->sd->groups; 5604 struct sched_group *sg = env->sd->groups;
@@ -4720,11 +5618,17 @@ static inline void update_sd_lb_stats(struct lb_env *env,
4720 if (local_group) { 5618 if (local_group) {
4721 sds->local = sg; 5619 sds->local = sg;
4722 sgs = &sds->local_stat; 5620 sgs = &sds->local_stat;
5621
5622 if (env->idle != CPU_NEWLY_IDLE ||
5623 time_after_eq(jiffies, sg->sgp->next_update))
5624 update_group_power(env->sd, env->dst_cpu);
4723 } 5625 }
4724 5626
4725 memset(sgs, 0, sizeof(*sgs));
4726 update_sg_lb_stats(env, sg, load_idx, local_group, sgs); 5627 update_sg_lb_stats(env, sg, load_idx, local_group, sgs);
4727 5628
5629 if (local_group)
5630 goto next_group;
5631
4728 /* 5632 /*
4729 * In case the child domain prefers tasks go to siblings 5633 * In case the child domain prefers tasks go to siblings
4730 * first, lower the sg capacity to one so that we'll try 5634 * first, lower the sg capacity to one so that we'll try
@@ -4735,21 +5639,25 @@ static inline void update_sd_lb_stats(struct lb_env *env,
4735 * heaviest group when it is already under-utilized (possible 5639 * heaviest group when it is already under-utilized (possible
4736 * with a large weight task outweighs the tasks on the system). 5640 * with a large weight task outweighs the tasks on the system).
4737 */ 5641 */
4738 if (prefer_sibling && !local_group && 5642 if (prefer_sibling && sds->local &&
4739 sds->local && sds->local_stat.group_has_capacity) 5643 sds->local_stat.group_has_capacity)
4740 sgs->group_capacity = min(sgs->group_capacity, 1U); 5644 sgs->group_capacity = min(sgs->group_capacity, 1U);
4741 5645
4742 /* Now, start updating sd_lb_stats */ 5646 if (update_sd_pick_busiest(env, sds, sg, sgs)) {
4743 sds->total_load += sgs->group_load;
4744 sds->total_pwr += sgs->group_power;
4745
4746 if (!local_group && update_sd_pick_busiest(env, sds, sg, sgs)) {
4747 sds->busiest = sg; 5647 sds->busiest = sg;
4748 sds->busiest_stat = *sgs; 5648 sds->busiest_stat = *sgs;
4749 } 5649 }
4750 5650
5651next_group:
5652 /* Now, start updating sd_lb_stats */
5653 sds->total_load += sgs->group_load;
5654 sds->total_pwr += sgs->group_power;
5655
4751 sg = sg->next; 5656 sg = sg->next;
4752 } while (sg != env->sd->groups); 5657 } while (sg != env->sd->groups);
5658
5659 if (env->sd->flags & SD_NUMA)
5660 env->fbq_type = fbq_classify_group(&sds->busiest_stat);
4753} 5661}
4754 5662
4755/** 5663/**
@@ -5053,15 +5961,39 @@ static struct rq *find_busiest_queue(struct lb_env *env,
5053 int i; 5961 int i;
5054 5962
5055 for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { 5963 for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
5056 unsigned long power = power_of(i); 5964 unsigned long power, capacity, wl;
5057 unsigned long capacity = DIV_ROUND_CLOSEST(power, 5965 enum fbq_type rt;
5058 SCHED_POWER_SCALE); 5966
5059 unsigned long wl; 5967 rq = cpu_rq(i);
5968 rt = fbq_classify_rq(rq);
5969
5970 /*
5971 * We classify groups/runqueues into three groups:
5972 * - regular: there are !numa tasks
5973 * - remote: there are numa tasks that run on the 'wrong' node
5974 * - all: there is no distinction
5975 *
5976 * In order to avoid migrating ideally placed numa tasks,
5977 * ignore those when there's better options.
5978 *
5979 * If we ignore the actual busiest queue to migrate another
5980 * task, the next balance pass can still reduce the busiest
5981 * queue by moving tasks around inside the node.
5982 *
5983 * If we cannot move enough load due to this classification
5984 * the next pass will adjust the group classification and
5985 * allow migration of more tasks.
5986 *
5987 * Both cases only affect the total convergence complexity.
5988 */
5989 if (rt > env->fbq_type)
5990 continue;
5060 5991
5992 power = power_of(i);
5993 capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
5061 if (!capacity) 5994 if (!capacity)
5062 capacity = fix_small_capacity(env->sd, group); 5995 capacity = fix_small_capacity(env->sd, group);
5063 5996
5064 rq = cpu_rq(i);
5065 wl = weighted_cpuload(i); 5997 wl = weighted_cpuload(i);
5066 5998
5067 /* 5999 /*
@@ -5164,6 +6096,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
5164 int *continue_balancing) 6096 int *continue_balancing)
5165{ 6097{
5166 int ld_moved, cur_ld_moved, active_balance = 0; 6098 int ld_moved, cur_ld_moved, active_balance = 0;
6099 struct sched_domain *sd_parent = sd->parent;
5167 struct sched_group *group; 6100 struct sched_group *group;
5168 struct rq *busiest; 6101 struct rq *busiest;
5169 unsigned long flags; 6102 unsigned long flags;
@@ -5177,6 +6110,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
5177 .idle = idle, 6110 .idle = idle,
5178 .loop_break = sched_nr_migrate_break, 6111 .loop_break = sched_nr_migrate_break,
5179 .cpus = cpus, 6112 .cpus = cpus,
6113 .fbq_type = all,
5180 }; 6114 };
5181 6115
5182 /* 6116 /*
@@ -5268,17 +6202,17 @@ more_balance:
5268 * moreover subsequent load balance cycles should correct the 6202 * moreover subsequent load balance cycles should correct the
5269 * excess load moved. 6203 * excess load moved.
5270 */ 6204 */
5271 if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) { 6205 if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) {
6206
6207 /* Prevent to re-select dst_cpu via env's cpus */
6208 cpumask_clear_cpu(env.dst_cpu, env.cpus);
5272 6209
5273 env.dst_rq = cpu_rq(env.new_dst_cpu); 6210 env.dst_rq = cpu_rq(env.new_dst_cpu);
5274 env.dst_cpu = env.new_dst_cpu; 6211 env.dst_cpu = env.new_dst_cpu;
5275 env.flags &= ~LBF_SOME_PINNED; 6212 env.flags &= ~LBF_DST_PINNED;
5276 env.loop = 0; 6213 env.loop = 0;
5277 env.loop_break = sched_nr_migrate_break; 6214 env.loop_break = sched_nr_migrate_break;
5278 6215
5279 /* Prevent to re-select dst_cpu via env's cpus */
5280 cpumask_clear_cpu(env.dst_cpu, env.cpus);
5281
5282 /* 6216 /*
5283 * Go back to "more_balance" rather than "redo" since we 6217 * Go back to "more_balance" rather than "redo" since we
5284 * need to continue with same src_cpu. 6218 * need to continue with same src_cpu.
@@ -5286,6 +6220,18 @@ more_balance:
5286 goto more_balance; 6220 goto more_balance;
5287 } 6221 }
5288 6222
6223 /*
6224 * We failed to reach balance because of affinity.
6225 */
6226 if (sd_parent) {
6227 int *group_imbalance = &sd_parent->groups->sgp->imbalance;
6228
6229 if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) {
6230 *group_imbalance = 1;
6231 } else if (*group_imbalance)
6232 *group_imbalance = 0;
6233 }
6234
5289 /* All tasks on this runqueue were pinned by CPU affinity */ 6235 /* All tasks on this runqueue were pinned by CPU affinity */
5290 if (unlikely(env.flags & LBF_ALL_PINNED)) { 6236 if (unlikely(env.flags & LBF_ALL_PINNED)) {
5291 cpumask_clear_cpu(cpu_of(busiest), cpus); 6237 cpumask_clear_cpu(cpu_of(busiest), cpus);
@@ -5393,6 +6339,7 @@ void idle_balance(int this_cpu, struct rq *this_rq)
5393 struct sched_domain *sd; 6339 struct sched_domain *sd;
5394 int pulled_task = 0; 6340 int pulled_task = 0;
5395 unsigned long next_balance = jiffies + HZ; 6341 unsigned long next_balance = jiffies + HZ;
6342 u64 curr_cost = 0;
5396 6343
5397 this_rq->idle_stamp = rq_clock(this_rq); 6344 this_rq->idle_stamp = rq_clock(this_rq);
5398 6345
@@ -5409,15 +6356,27 @@ void idle_balance(int this_cpu, struct rq *this_rq)
5409 for_each_domain(this_cpu, sd) { 6356 for_each_domain(this_cpu, sd) {
5410 unsigned long interval; 6357 unsigned long interval;
5411 int continue_balancing = 1; 6358 int continue_balancing = 1;
6359 u64 t0, domain_cost;
5412 6360
5413 if (!(sd->flags & SD_LOAD_BALANCE)) 6361 if (!(sd->flags & SD_LOAD_BALANCE))
5414 continue; 6362 continue;
5415 6363
6364 if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost)
6365 break;
6366
5416 if (sd->flags & SD_BALANCE_NEWIDLE) { 6367 if (sd->flags & SD_BALANCE_NEWIDLE) {
6368 t0 = sched_clock_cpu(this_cpu);
6369
5417 /* If we've pulled tasks over stop searching: */ 6370 /* If we've pulled tasks over stop searching: */
5418 pulled_task = load_balance(this_cpu, this_rq, 6371 pulled_task = load_balance(this_cpu, this_rq,
5419 sd, CPU_NEWLY_IDLE, 6372 sd, CPU_NEWLY_IDLE,
5420 &continue_balancing); 6373 &continue_balancing);
6374
6375 domain_cost = sched_clock_cpu(this_cpu) - t0;
6376 if (domain_cost > sd->max_newidle_lb_cost)
6377 sd->max_newidle_lb_cost = domain_cost;
6378
6379 curr_cost += domain_cost;
5421 } 6380 }
5422 6381
5423 interval = msecs_to_jiffies(sd->balance_interval); 6382 interval = msecs_to_jiffies(sd->balance_interval);
@@ -5439,6 +6398,9 @@ void idle_balance(int this_cpu, struct rq *this_rq)
5439 */ 6398 */
5440 this_rq->next_balance = next_balance; 6399 this_rq->next_balance = next_balance;
5441 } 6400 }
6401
6402 if (curr_cost > this_rq->max_idle_balance_cost)
6403 this_rq->max_idle_balance_cost = curr_cost;
5442} 6404}
5443 6405
5444/* 6406/*
@@ -5572,16 +6534,16 @@ static inline void nohz_balance_exit_idle(int cpu)
5572static inline void set_cpu_sd_state_busy(void) 6534static inline void set_cpu_sd_state_busy(void)
5573{ 6535{
5574 struct sched_domain *sd; 6536 struct sched_domain *sd;
6537 int cpu = smp_processor_id();
5575 6538
5576 rcu_read_lock(); 6539 rcu_read_lock();
5577 sd = rcu_dereference_check_sched_domain(this_rq()->sd); 6540 sd = rcu_dereference(per_cpu(sd_busy, cpu));
5578 6541
5579 if (!sd || !sd->nohz_idle) 6542 if (!sd || !sd->nohz_idle)
5580 goto unlock; 6543 goto unlock;
5581 sd->nohz_idle = 0; 6544 sd->nohz_idle = 0;
5582 6545
5583 for (; sd; sd = sd->parent) 6546 atomic_inc(&sd->groups->sgp->nr_busy_cpus);
5584 atomic_inc(&sd->groups->sgp->nr_busy_cpus);
5585unlock: 6547unlock:
5586 rcu_read_unlock(); 6548 rcu_read_unlock();
5587} 6549}
@@ -5589,16 +6551,16 @@ unlock:
5589void set_cpu_sd_state_idle(void) 6551void set_cpu_sd_state_idle(void)
5590{ 6552{
5591 struct sched_domain *sd; 6553 struct sched_domain *sd;
6554 int cpu = smp_processor_id();
5592 6555
5593 rcu_read_lock(); 6556 rcu_read_lock();
5594 sd = rcu_dereference_check_sched_domain(this_rq()->sd); 6557 sd = rcu_dereference(per_cpu(sd_busy, cpu));
5595 6558
5596 if (!sd || sd->nohz_idle) 6559 if (!sd || sd->nohz_idle)
5597 goto unlock; 6560 goto unlock;
5598 sd->nohz_idle = 1; 6561 sd->nohz_idle = 1;
5599 6562
5600 for (; sd; sd = sd->parent) 6563 atomic_dec(&sd->groups->sgp->nr_busy_cpus);
5601 atomic_dec(&sd->groups->sgp->nr_busy_cpus);
5602unlock: 6564unlock:
5603 rcu_read_unlock(); 6565 rcu_read_unlock();
5604} 6566}
@@ -5662,15 +6624,39 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
5662 /* Earliest time when we have to do rebalance again */ 6624 /* Earliest time when we have to do rebalance again */
5663 unsigned long next_balance = jiffies + 60*HZ; 6625 unsigned long next_balance = jiffies + 60*HZ;
5664 int update_next_balance = 0; 6626 int update_next_balance = 0;
5665 int need_serialize; 6627 int need_serialize, need_decay = 0;
6628 u64 max_cost = 0;
5666 6629
5667 update_blocked_averages(cpu); 6630 update_blocked_averages(cpu);
5668 6631
5669 rcu_read_lock(); 6632 rcu_read_lock();
5670 for_each_domain(cpu, sd) { 6633 for_each_domain(cpu, sd) {
6634 /*
6635 * Decay the newidle max times here because this is a regular
6636 * visit to all the domains. Decay ~1% per second.
6637 */
6638 if (time_after(jiffies, sd->next_decay_max_lb_cost)) {
6639 sd->max_newidle_lb_cost =
6640 (sd->max_newidle_lb_cost * 253) / 256;
6641 sd->next_decay_max_lb_cost = jiffies + HZ;
6642 need_decay = 1;
6643 }
6644 max_cost += sd->max_newidle_lb_cost;
6645
5671 if (!(sd->flags & SD_LOAD_BALANCE)) 6646 if (!(sd->flags & SD_LOAD_BALANCE))
5672 continue; 6647 continue;
5673 6648
6649 /*
6650 * Stop the load balance at this level. There is another
6651 * CPU in our sched group which is doing load balancing more
6652 * actively.
6653 */
6654 if (!continue_balancing) {
6655 if (need_decay)
6656 continue;
6657 break;
6658 }
6659
5674 interval = sd->balance_interval; 6660 interval = sd->balance_interval;
5675 if (idle != CPU_IDLE) 6661 if (idle != CPU_IDLE)
5676 interval *= sd->busy_factor; 6662 interval *= sd->busy_factor;
@@ -5689,7 +6675,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
5689 if (time_after_eq(jiffies, sd->last_balance + interval)) { 6675 if (time_after_eq(jiffies, sd->last_balance + interval)) {
5690 if (load_balance(cpu, rq, sd, idle, &continue_balancing)) { 6676 if (load_balance(cpu, rq, sd, idle, &continue_balancing)) {
5691 /* 6677 /*
5692 * The LBF_SOME_PINNED logic could have changed 6678 * The LBF_DST_PINNED logic could have changed
5693 * env->dst_cpu, so we can't know our idle 6679 * env->dst_cpu, so we can't know our idle
5694 * state even if we migrated tasks. Update it. 6680 * state even if we migrated tasks. Update it.
5695 */ 6681 */
@@ -5704,14 +6690,14 @@ out:
5704 next_balance = sd->last_balance + interval; 6690 next_balance = sd->last_balance + interval;
5705 update_next_balance = 1; 6691 update_next_balance = 1;
5706 } 6692 }
5707 6693 }
6694 if (need_decay) {
5708 /* 6695 /*
5709 * Stop the load balance at this level. There is another 6696 * Ensure the rq-wide value also decays but keep it at a
5710 * CPU in our sched group which is doing load balancing more 6697 * reasonable floor to avoid funnies with rq->avg_idle.
5711 * actively.
5712 */ 6698 */
5713 if (!continue_balancing) 6699 rq->max_idle_balance_cost =
5714 break; 6700 max((u64)sysctl_sched_migration_cost, max_cost);
5715 } 6701 }
5716 rcu_read_unlock(); 6702 rcu_read_unlock();
5717 6703
@@ -5781,6 +6767,8 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu)
5781{ 6767{
5782 unsigned long now = jiffies; 6768 unsigned long now = jiffies;
5783 struct sched_domain *sd; 6769 struct sched_domain *sd;
6770 struct sched_group_power *sgp;
6771 int nr_busy;
5784 6772
5785 if (unlikely(idle_cpu(cpu))) 6773 if (unlikely(idle_cpu(cpu)))
5786 return 0; 6774 return 0;
@@ -5806,22 +6794,22 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu)
5806 goto need_kick; 6794 goto need_kick;
5807 6795
5808 rcu_read_lock(); 6796 rcu_read_lock();
5809 for_each_domain(cpu, sd) { 6797 sd = rcu_dereference(per_cpu(sd_busy, cpu));
5810 struct sched_group *sg = sd->groups;
5811 struct sched_group_power *sgp = sg->sgp;
5812 int nr_busy = atomic_read(&sgp->nr_busy_cpus);
5813 6798
5814 if (sd->flags & SD_SHARE_PKG_RESOURCES && nr_busy > 1) 6799 if (sd) {
5815 goto need_kick_unlock; 6800 sgp = sd->groups->sgp;
6801 nr_busy = atomic_read(&sgp->nr_busy_cpus);
5816 6802
5817 if (sd->flags & SD_ASYM_PACKING && nr_busy != sg->group_weight 6803 if (nr_busy > 1)
5818 && (cpumask_first_and(nohz.idle_cpus_mask,
5819 sched_domain_span(sd)) < cpu))
5820 goto need_kick_unlock; 6804 goto need_kick_unlock;
5821
5822 if (!(sd->flags & (SD_SHARE_PKG_RESOURCES | SD_ASYM_PACKING)))
5823 break;
5824 } 6805 }
6806
6807 sd = rcu_dereference(per_cpu(sd_asym, cpu));
6808
6809 if (sd && (cpumask_first_and(nohz.idle_cpus_mask,
6810 sched_domain_span(sd)) < cpu))
6811 goto need_kick_unlock;
6812
5825 rcu_read_unlock(); 6813 rcu_read_unlock();
5826 return 0; 6814 return 0;
5827 6815
@@ -6214,7 +7202,8 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
6214 se->cfs_rq = parent->my_q; 7202 se->cfs_rq = parent->my_q;
6215 7203
6216 se->my_q = cfs_rq; 7204 se->my_q = cfs_rq;
6217 update_load_set(&se->load, 0); 7205 /* guarantee group entities always have weight */
7206 update_load_set(&se->load, NICE_0_LOAD);
6218 se->parent = parent; 7207 se->parent = parent;
6219} 7208}
6220 7209
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 99399f8e4799..5716929a2e3a 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -63,10 +63,23 @@ SCHED_FEAT(LB_MIN, false)
63/* 63/*
64 * Apply the automatic NUMA scheduling policy. Enabled automatically 64 * Apply the automatic NUMA scheduling policy. Enabled automatically
65 * at runtime if running on a NUMA machine. Can be controlled via 65 * at runtime if running on a NUMA machine. Can be controlled via
66 * numa_balancing=. Allow PTE scanning to be forced on UMA machines 66 * numa_balancing=
67 * for debugging the core machinery.
68 */ 67 */
69#ifdef CONFIG_NUMA_BALANCING 68#ifdef CONFIG_NUMA_BALANCING
70SCHED_FEAT(NUMA, false) 69SCHED_FEAT(NUMA, false)
71SCHED_FEAT(NUMA_FORCE, false) 70
71/*
72 * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a
73 * higher number of hinting faults are recorded during active load
74 * balancing.
75 */
76SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
77
78/*
79 * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a
80 * lower number of hinting faults have been recorded. As this has
81 * the potential to prevent a task ever migrating to a new node
82 * due to CPU overload it is disabled by default.
83 */
84SCHED_FEAT(NUMA_RESIST_LOWER, false)
72#endif 85#endif
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
index d8da01008d39..516c3d9ceea1 100644
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -9,7 +9,7 @@
9 9
10#ifdef CONFIG_SMP 10#ifdef CONFIG_SMP
11static int 11static int
12select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) 12select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
13{ 13{
14 return task_cpu(p); /* IDLE tasks as never migrated */ 14 return task_cpu(p); /* IDLE tasks as never migrated */
15} 15}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 01970c8e64df..7d57275fc396 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -246,8 +246,10 @@ static inline void rt_set_overload(struct rq *rq)
246 * if we should look at the mask. It would be a shame 246 * if we should look at the mask. It would be a shame
247 * if we looked at the mask, but the mask was not 247 * if we looked at the mask, but the mask was not
248 * updated yet. 248 * updated yet.
249 *
250 * Matched by the barrier in pull_rt_task().
249 */ 251 */
250 wmb(); 252 smp_wmb();
251 atomic_inc(&rq->rd->rto_count); 253 atomic_inc(&rq->rd->rto_count);
252} 254}
253 255
@@ -1169,13 +1171,10 @@ static void yield_task_rt(struct rq *rq)
1169static int find_lowest_rq(struct task_struct *task); 1171static int find_lowest_rq(struct task_struct *task);
1170 1172
1171static int 1173static int
1172select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) 1174select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
1173{ 1175{
1174 struct task_struct *curr; 1176 struct task_struct *curr;
1175 struct rq *rq; 1177 struct rq *rq;
1176 int cpu;
1177
1178 cpu = task_cpu(p);
1179 1178
1180 if (p->nr_cpus_allowed == 1) 1179 if (p->nr_cpus_allowed == 1)
1181 goto out; 1180 goto out;
@@ -1213,8 +1212,7 @@ select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
1213 */ 1212 */
1214 if (curr && unlikely(rt_task(curr)) && 1213 if (curr && unlikely(rt_task(curr)) &&
1215 (curr->nr_cpus_allowed < 2 || 1214 (curr->nr_cpus_allowed < 2 ||
1216 curr->prio <= p->prio) && 1215 curr->prio <= p->prio)) {
1217 (p->nr_cpus_allowed > 1)) {
1218 int target = find_lowest_rq(p); 1216 int target = find_lowest_rq(p);
1219 1217
1220 if (target != -1) 1218 if (target != -1)
@@ -1630,6 +1628,12 @@ static int pull_rt_task(struct rq *this_rq)
1630 if (likely(!rt_overloaded(this_rq))) 1628 if (likely(!rt_overloaded(this_rq)))
1631 return 0; 1629 return 0;
1632 1630
1631 /*
1632 * Match the barrier from rt_set_overloaded; this guarantees that if we
1633 * see overloaded we must also see the rto_mask bit.
1634 */
1635 smp_rmb();
1636
1633 for_each_cpu(cpu, this_rq->rd->rto_mask) { 1637 for_each_cpu(cpu, this_rq->rd->rto_mask) {
1634 if (this_cpu == cpu) 1638 if (this_cpu == cpu)
1635 continue; 1639 continue;
@@ -1931,8 +1935,8 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
1931 p->rt.time_slice = sched_rr_timeslice; 1935 p->rt.time_slice = sched_rr_timeslice;
1932 1936
1933 /* 1937 /*
1934 * Requeue to the end of queue if we (and all of our ancestors) are the 1938 * Requeue to the end of queue if we (and all of our ancestors) are not
1935 * only element on the queue 1939 * the only element on the queue
1936 */ 1940 */
1937 for_each_sched_rt_entity(rt_se) { 1941 for_each_sched_rt_entity(rt_se) {
1938 if (rt_se->run_list.prev != rt_se->run_list.next) { 1942 if (rt_se->run_list.prev != rt_se->run_list.next) {
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b3c5653e1dca..88c85b21d633 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -6,6 +6,7 @@
6#include <linux/spinlock.h> 6#include <linux/spinlock.h>
7#include <linux/stop_machine.h> 7#include <linux/stop_machine.h>
8#include <linux/tick.h> 8#include <linux/tick.h>
9#include <linux/slab.h>
9 10
10#include "cpupri.h" 11#include "cpupri.h"
11#include "cpuacct.h" 12#include "cpuacct.h"
@@ -408,6 +409,10 @@ struct rq {
408 * remote CPUs use both these fields when doing load calculation. 409 * remote CPUs use both these fields when doing load calculation.
409 */ 410 */
410 unsigned int nr_running; 411 unsigned int nr_running;
412#ifdef CONFIG_NUMA_BALANCING
413 unsigned int nr_numa_running;
414 unsigned int nr_preferred_running;
415#endif
411 #define CPU_LOAD_IDX_MAX 5 416 #define CPU_LOAD_IDX_MAX 5
412 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 417 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
413 unsigned long last_load_update_tick; 418 unsigned long last_load_update_tick;
@@ -476,6 +481,9 @@ struct rq {
476 u64 age_stamp; 481 u64 age_stamp;
477 u64 idle_stamp; 482 u64 idle_stamp;
478 u64 avg_idle; 483 u64 avg_idle;
484
485 /* This is used to determine avg_idle's max value */
486 u64 max_idle_balance_cost;
479#endif 487#endif
480 488
481#ifdef CONFIG_IRQ_TIME_ACCOUNTING 489#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -552,6 +560,12 @@ static inline u64 rq_clock_task(struct rq *rq)
552 return rq->clock_task; 560 return rq->clock_task;
553} 561}
554 562
563#ifdef CONFIG_NUMA_BALANCING
564extern void sched_setnuma(struct task_struct *p, int node);
565extern int migrate_task_to(struct task_struct *p, int cpu);
566extern int migrate_swap(struct task_struct *, struct task_struct *);
567#endif /* CONFIG_NUMA_BALANCING */
568
555#ifdef CONFIG_SMP 569#ifdef CONFIG_SMP
556 570
557#define rcu_dereference_check_sched_domain(p) \ 571#define rcu_dereference_check_sched_domain(p) \
@@ -593,9 +607,24 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
593 return hsd; 607 return hsd;
594} 608}
595 609
610static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
611{
612 struct sched_domain *sd;
613
614 for_each_domain(cpu, sd) {
615 if (sd->flags & flag)
616 break;
617 }
618
619 return sd;
620}
621
596DECLARE_PER_CPU(struct sched_domain *, sd_llc); 622DECLARE_PER_CPU(struct sched_domain *, sd_llc);
597DECLARE_PER_CPU(int, sd_llc_size); 623DECLARE_PER_CPU(int, sd_llc_size);
598DECLARE_PER_CPU(int, sd_llc_id); 624DECLARE_PER_CPU(int, sd_llc_id);
625DECLARE_PER_CPU(struct sched_domain *, sd_numa);
626DECLARE_PER_CPU(struct sched_domain *, sd_busy);
627DECLARE_PER_CPU(struct sched_domain *, sd_asym);
599 628
600struct sched_group_power { 629struct sched_group_power {
601 atomic_t ref; 630 atomic_t ref;
@@ -605,6 +634,7 @@ struct sched_group_power {
605 */ 634 */
606 unsigned int power, power_orig; 635 unsigned int power, power_orig;
607 unsigned long next_update; 636 unsigned long next_update;
637 int imbalance; /* XXX unrelated to power but shared group state */
608 /* 638 /*
609 * Number of busy cpus in this group. 639 * Number of busy cpus in this group.
610 */ 640 */
@@ -719,6 +749,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
719 */ 749 */
720 smp_wmb(); 750 smp_wmb();
721 task_thread_info(p)->cpu = cpu; 751 task_thread_info(p)->cpu = cpu;
752 p->wake_cpu = cpu;
722#endif 753#endif
723} 754}
724 755
@@ -974,7 +1005,7 @@ struct sched_class {
974 void (*put_prev_task) (struct rq *rq, struct task_struct *p); 1005 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
975 1006
976#ifdef CONFIG_SMP 1007#ifdef CONFIG_SMP
977 int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags); 1008 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
978 void (*migrate_task_rq)(struct task_struct *p, int next_cpu); 1009 void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
979 1010
980 void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); 1011 void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
@@ -1220,6 +1251,24 @@ static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1220 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 1251 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1221} 1252}
1222 1253
1254static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1255{
1256 if (l1 > l2)
1257 swap(l1, l2);
1258
1259 spin_lock(l1);
1260 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1261}
1262
1263static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1264{
1265 if (l1 > l2)
1266 swap(l1, l2);
1267
1268 raw_spin_lock(l1);
1269 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1270}
1271
1223/* 1272/*
1224 * double_rq_lock - safely lock two runqueues 1273 * double_rq_lock - safely lock two runqueues
1225 * 1274 *
@@ -1305,7 +1354,8 @@ extern void print_rt_stats(struct seq_file *m, int cpu);
1305extern void init_cfs_rq(struct cfs_rq *cfs_rq); 1354extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1306extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq); 1355extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1307 1356
1308extern void account_cfs_bandwidth_used(int enabled, int was_enabled); 1357extern void cfs_bandwidth_usage_inc(void);
1358extern void cfs_bandwidth_usage_dec(void);
1309 1359
1310#ifdef CONFIG_NO_HZ_COMMON 1360#ifdef CONFIG_NO_HZ_COMMON
1311enum rq_nohz_flag_bits { 1361enum rq_nohz_flag_bits {
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index c7edee71bce8..4ab704339656 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -59,9 +59,9 @@ static inline void sched_info_reset_dequeued(struct task_struct *t)
59 * from dequeue_task() to account for possible rq->clock skew across cpus. The 59 * from dequeue_task() to account for possible rq->clock skew across cpus. The
60 * delta taken on each cpu would annul the skew. 60 * delta taken on each cpu would annul the skew.
61 */ 61 */
62static inline void sched_info_dequeued(struct task_struct *t) 62static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
63{ 63{
64 unsigned long long now = rq_clock(task_rq(t)), delta = 0; 64 unsigned long long now = rq_clock(rq), delta = 0;
65 65
66 if (unlikely(sched_info_on())) 66 if (unlikely(sched_info_on()))
67 if (t->sched_info.last_queued) 67 if (t->sched_info.last_queued)
@@ -69,7 +69,7 @@ static inline void sched_info_dequeued(struct task_struct *t)
69 sched_info_reset_dequeued(t); 69 sched_info_reset_dequeued(t);
70 t->sched_info.run_delay += delta; 70 t->sched_info.run_delay += delta;
71 71
72 rq_sched_info_dequeued(task_rq(t), delta); 72 rq_sched_info_dequeued(rq, delta);
73} 73}
74 74
75/* 75/*
@@ -77,9 +77,9 @@ static inline void sched_info_dequeued(struct task_struct *t)
77 * long it was waiting to run. We also note when it began so that we 77 * long it was waiting to run. We also note when it began so that we
78 * can keep stats on how long its timeslice is. 78 * can keep stats on how long its timeslice is.
79 */ 79 */
80static void sched_info_arrive(struct task_struct *t) 80static void sched_info_arrive(struct rq *rq, struct task_struct *t)
81{ 81{
82 unsigned long long now = rq_clock(task_rq(t)), delta = 0; 82 unsigned long long now = rq_clock(rq), delta = 0;
83 83
84 if (t->sched_info.last_queued) 84 if (t->sched_info.last_queued)
85 delta = now - t->sched_info.last_queued; 85 delta = now - t->sched_info.last_queued;
@@ -88,7 +88,7 @@ static void sched_info_arrive(struct task_struct *t)
88 t->sched_info.last_arrival = now; 88 t->sched_info.last_arrival = now;
89 t->sched_info.pcount++; 89 t->sched_info.pcount++;
90 90
91 rq_sched_info_arrive(task_rq(t), delta); 91 rq_sched_info_arrive(rq, delta);
92} 92}
93 93
94/* 94/*
@@ -96,11 +96,11 @@ static void sched_info_arrive(struct task_struct *t)
96 * the timestamp if it is already not set. It's assumed that 96 * the timestamp if it is already not set. It's assumed that
97 * sched_info_dequeued() will clear that stamp when appropriate. 97 * sched_info_dequeued() will clear that stamp when appropriate.
98 */ 98 */
99static inline void sched_info_queued(struct task_struct *t) 99static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
100{ 100{
101 if (unlikely(sched_info_on())) 101 if (unlikely(sched_info_on()))
102 if (!t->sched_info.last_queued) 102 if (!t->sched_info.last_queued)
103 t->sched_info.last_queued = rq_clock(task_rq(t)); 103 t->sched_info.last_queued = rq_clock(rq);
104} 104}
105 105
106/* 106/*
@@ -111,15 +111,15 @@ static inline void sched_info_queued(struct task_struct *t)
111 * sched_info_queued() to mark that it has now again started waiting on 111 * sched_info_queued() to mark that it has now again started waiting on
112 * the runqueue. 112 * the runqueue.
113 */ 113 */
114static inline void sched_info_depart(struct task_struct *t) 114static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
115{ 115{
116 unsigned long long delta = rq_clock(task_rq(t)) - 116 unsigned long long delta = rq_clock(rq) -
117 t->sched_info.last_arrival; 117 t->sched_info.last_arrival;
118 118
119 rq_sched_info_depart(task_rq(t), delta); 119 rq_sched_info_depart(rq, delta);
120 120
121 if (t->state == TASK_RUNNING) 121 if (t->state == TASK_RUNNING)
122 sched_info_queued(t); 122 sched_info_queued(rq, t);
123} 123}
124 124
125/* 125/*
@@ -128,32 +128,34 @@ static inline void sched_info_depart(struct task_struct *t)
128 * the idle task.) We are only called when prev != next. 128 * the idle task.) We are only called when prev != next.
129 */ 129 */
130static inline void 130static inline void
131__sched_info_switch(struct task_struct *prev, struct task_struct *next) 131__sched_info_switch(struct rq *rq,
132 struct task_struct *prev, struct task_struct *next)
132{ 133{
133 struct rq *rq = task_rq(prev);
134
135 /* 134 /*
136 * prev now departs the cpu. It's not interesting to record 135 * prev now departs the cpu. It's not interesting to record
137 * stats about how efficient we were at scheduling the idle 136 * stats about how efficient we were at scheduling the idle
138 * process, however. 137 * process, however.
139 */ 138 */
140 if (prev != rq->idle) 139 if (prev != rq->idle)
141 sched_info_depart(prev); 140 sched_info_depart(rq, prev);
142 141
143 if (next != rq->idle) 142 if (next != rq->idle)
144 sched_info_arrive(next); 143 sched_info_arrive(rq, next);
145} 144}
146static inline void 145static inline void
147sched_info_switch(struct task_struct *prev, struct task_struct *next) 146sched_info_switch(struct rq *rq,
147 struct task_struct *prev, struct task_struct *next)
148{ 148{
149 if (unlikely(sched_info_on())) 149 if (unlikely(sched_info_on()))
150 __sched_info_switch(prev, next); 150 __sched_info_switch(rq, prev, next);
151} 151}
152#else 152#else
153#define sched_info_queued(t) do { } while (0) 153#define sched_info_queued(rq, t) do { } while (0)
154#define sched_info_reset_dequeued(t) do { } while (0) 154#define sched_info_reset_dequeued(t) do { } while (0)
155#define sched_info_dequeued(t) do { } while (0) 155#define sched_info_dequeued(rq, t) do { } while (0)
156#define sched_info_switch(t, next) do { } while (0) 156#define sched_info_depart(rq, t) do { } while (0)
157#define sched_info_arrive(rq, next) do { } while (0)
158#define sched_info_switch(rq, t, next) do { } while (0)
157#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */ 159#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
158 160
159/* 161/*
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index e08fbeeb54b9..47197de8abd9 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -11,7 +11,7 @@
11 11
12#ifdef CONFIG_SMP 12#ifdef CONFIG_SMP
13static int 13static int
14select_task_rq_stop(struct task_struct *p, int sd_flag, int flags) 14select_task_rq_stop(struct task_struct *p, int cpu, int sd_flag, int flags)
15{ 15{
16 return task_cpu(p); /* stop tasks as never migrate */ 16 return task_cpu(p); /* stop tasks as never migrate */
17} 17}
diff --git a/kernel/wait.c b/kernel/sched/wait.c
index d550920e040c..7d50f794e248 100644
--- a/kernel/wait.c
+++ b/kernel/sched/wait.c
@@ -53,6 +53,109 @@ EXPORT_SYMBOL(remove_wait_queue);
53 53
54 54
55/* 55/*
56 * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
57 * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
58 * number) then we wake all the non-exclusive tasks and one exclusive task.
59 *
60 * There are circumstances in which we can try to wake a task which has already
61 * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
62 * zero in this (rare) case, and we handle it by continuing to scan the queue.
63 */
64static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
65 int nr_exclusive, int wake_flags, void *key)
66{
67 wait_queue_t *curr, *next;
68
69 list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
70 unsigned flags = curr->flags;
71
72 if (curr->func(curr, mode, wake_flags, key) &&
73 (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
74 break;
75 }
76}
77
78/**
79 * __wake_up - wake up threads blocked on a waitqueue.
80 * @q: the waitqueue
81 * @mode: which threads
82 * @nr_exclusive: how many wake-one or wake-many threads to wake up
83 * @key: is directly passed to the wakeup function
84 *
85 * It may be assumed that this function implies a write memory barrier before
86 * changing the task state if and only if any tasks are woken up.
87 */
88void __wake_up(wait_queue_head_t *q, unsigned int mode,
89 int nr_exclusive, void *key)
90{
91 unsigned long flags;
92
93 spin_lock_irqsave(&q->lock, flags);
94 __wake_up_common(q, mode, nr_exclusive, 0, key);
95 spin_unlock_irqrestore(&q->lock, flags);
96}
97EXPORT_SYMBOL(__wake_up);
98
99/*
100 * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
101 */
102void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
103{
104 __wake_up_common(q, mode, nr, 0, NULL);
105}
106EXPORT_SYMBOL_GPL(__wake_up_locked);
107
108void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
109{
110 __wake_up_common(q, mode, 1, 0, key);
111}
112EXPORT_SYMBOL_GPL(__wake_up_locked_key);
113
114/**
115 * __wake_up_sync_key - wake up threads blocked on a waitqueue.
116 * @q: the waitqueue
117 * @mode: which threads
118 * @nr_exclusive: how many wake-one or wake-many threads to wake up
119 * @key: opaque value to be passed to wakeup targets
120 *
121 * The sync wakeup differs that the waker knows that it will schedule
122 * away soon, so while the target thread will be woken up, it will not
123 * be migrated to another CPU - ie. the two threads are 'synchronized'
124 * with each other. This can prevent needless bouncing between CPUs.
125 *
126 * On UP it can prevent extra preemption.
127 *
128 * It may be assumed that this function implies a write memory barrier before
129 * changing the task state if and only if any tasks are woken up.
130 */
131void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
132 int nr_exclusive, void *key)
133{
134 unsigned long flags;
135 int wake_flags = 1; /* XXX WF_SYNC */
136
137 if (unlikely(!q))
138 return;
139
140 if (unlikely(nr_exclusive != 1))
141 wake_flags = 0;
142
143 spin_lock_irqsave(&q->lock, flags);
144 __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
145 spin_unlock_irqrestore(&q->lock, flags);
146}
147EXPORT_SYMBOL_GPL(__wake_up_sync_key);
148
149/*
150 * __wake_up_sync - see __wake_up_sync_key()
151 */
152void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
153{
154 __wake_up_sync_key(q, mode, nr_exclusive, NULL);
155}
156EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
157
158/*
56 * Note: we use "set_current_state()" _after_ the wait-queue add, 159 * Note: we use "set_current_state()" _after_ the wait-queue add,
57 * because we need a memory barrier there on SMP, so that any 160 * because we need a memory barrier there on SMP, so that any
58 * wake-function that tests for the wait-queue being active 161 * wake-function that tests for the wait-queue being active
@@ -92,6 +195,30 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
92} 195}
93EXPORT_SYMBOL(prepare_to_wait_exclusive); 196EXPORT_SYMBOL(prepare_to_wait_exclusive);
94 197
198long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state)
199{
200 unsigned long flags;
201
202 if (signal_pending_state(state, current))
203 return -ERESTARTSYS;
204
205 wait->private = current;
206 wait->func = autoremove_wake_function;
207
208 spin_lock_irqsave(&q->lock, flags);
209 if (list_empty(&wait->task_list)) {
210 if (wait->flags & WQ_FLAG_EXCLUSIVE)
211 __add_wait_queue_tail(q, wait);
212 else
213 __add_wait_queue(q, wait);
214 }
215 set_current_state(state);
216 spin_unlock_irqrestore(&q->lock, flags);
217
218 return 0;
219}
220EXPORT_SYMBOL(prepare_to_wait_event);
221
95/** 222/**
96 * finish_wait - clean up after waiting in a queue 223 * finish_wait - clean up after waiting in a queue
97 * @q: waitqueue waited on 224 * @q: waitqueue waited on
diff --git a/kernel/softirq.c b/kernel/softirq.c
index dacd0ab51df4..b24988353458 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -99,13 +99,13 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt)
99 99
100 raw_local_irq_save(flags); 100 raw_local_irq_save(flags);
101 /* 101 /*
102 * The preempt tracer hooks into add_preempt_count and will break 102 * The preempt tracer hooks into preempt_count_add and will break
103 * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET 103 * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET
104 * is set and before current->softirq_enabled is cleared. 104 * is set and before current->softirq_enabled is cleared.
105 * We must manually increment preempt_count here and manually 105 * We must manually increment preempt_count here and manually
106 * call the trace_preempt_off later. 106 * call the trace_preempt_off later.
107 */ 107 */
108 preempt_count() += cnt; 108 __preempt_count_add(cnt);
109 /* 109 /*
110 * Were softirqs turned off above: 110 * Were softirqs turned off above:
111 */ 111 */
@@ -119,7 +119,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt)
119#else /* !CONFIG_TRACE_IRQFLAGS */ 119#else /* !CONFIG_TRACE_IRQFLAGS */
120static inline void __local_bh_disable(unsigned long ip, unsigned int cnt) 120static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
121{ 121{
122 add_preempt_count(cnt); 122 preempt_count_add(cnt);
123 barrier(); 123 barrier();
124} 124}
125#endif /* CONFIG_TRACE_IRQFLAGS */ 125#endif /* CONFIG_TRACE_IRQFLAGS */
@@ -137,7 +137,7 @@ static void __local_bh_enable(unsigned int cnt)
137 137
138 if (softirq_count() == cnt) 138 if (softirq_count() == cnt)
139 trace_softirqs_on(_RET_IP_); 139 trace_softirqs_on(_RET_IP_);
140 sub_preempt_count(cnt); 140 preempt_count_sub(cnt);
141} 141}
142 142
143/* 143/*
@@ -168,7 +168,7 @@ static inline void _local_bh_enable_ip(unsigned long ip)
168 * Keep preemption disabled until we are done with 168 * Keep preemption disabled until we are done with
169 * softirq processing: 169 * softirq processing:
170 */ 170 */
171 sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1); 171 preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1);
172 172
173 if (unlikely(!in_interrupt() && local_softirq_pending())) { 173 if (unlikely(!in_interrupt() && local_softirq_pending())) {
174 /* 174 /*
@@ -178,7 +178,7 @@ static inline void _local_bh_enable_ip(unsigned long ip)
178 do_softirq(); 178 do_softirq();
179 } 179 }
180 180
181 dec_preempt_count(); 181 preempt_count_dec();
182#ifdef CONFIG_TRACE_IRQFLAGS 182#ifdef CONFIG_TRACE_IRQFLAGS
183 local_irq_enable(); 183 local_irq_enable();
184#endif 184#endif
@@ -260,7 +260,7 @@ restart:
260 " exited with %08x?\n", vec_nr, 260 " exited with %08x?\n", vec_nr,
261 softirq_to_name[vec_nr], h->action, 261 softirq_to_name[vec_nr], h->action,
262 prev_count, preempt_count()); 262 prev_count, preempt_count());
263 preempt_count() = prev_count; 263 preempt_count_set(prev_count);
264 } 264 }
265 265
266 rcu_bh_qs(cpu); 266 rcu_bh_qs(cpu);
@@ -378,7 +378,7 @@ void irq_exit(void)
378 378
379 account_irq_exit_time(current); 379 account_irq_exit_time(current);
380 trace_hardirq_exit(); 380 trace_hardirq_exit();
381 sub_preempt_count(HARDIRQ_OFFSET); 381 preempt_count_sub(HARDIRQ_OFFSET);
382 if (!in_interrupt() && local_softirq_pending()) 382 if (!in_interrupt() && local_softirq_pending())
383 invoke_softirq(); 383 invoke_softirq();
384 384
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index c09f2955ae30..84571e09c907 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -20,6 +20,7 @@
20#include <linux/kallsyms.h> 20#include <linux/kallsyms.h>
21#include <linux/smpboot.h> 21#include <linux/smpboot.h>
22#include <linux/atomic.h> 22#include <linux/atomic.h>
23#include <linux/lglock.h>
23 24
24/* 25/*
25 * Structure to determine completion condition and record errors. May 26 * Structure to determine completion condition and record errors. May
@@ -43,6 +44,14 @@ static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
43static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task); 44static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task);
44static bool stop_machine_initialized = false; 45static bool stop_machine_initialized = false;
45 46
47/*
48 * Avoids a race between stop_two_cpus and global stop_cpus, where
49 * the stoppers could get queued up in reverse order, leading to
50 * system deadlock. Using an lglock means stop_two_cpus remains
51 * relatively cheap.
52 */
53DEFINE_STATIC_LGLOCK(stop_cpus_lock);
54
46static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo) 55static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo)
47{ 56{
48 memset(done, 0, sizeof(*done)); 57 memset(done, 0, sizeof(*done));
@@ -115,6 +124,184 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
115 return done.executed ? done.ret : -ENOENT; 124 return done.executed ? done.ret : -ENOENT;
116} 125}
117 126
127/* This controls the threads on each CPU. */
128enum multi_stop_state {
129 /* Dummy starting state for thread. */
130 MULTI_STOP_NONE,
131 /* Awaiting everyone to be scheduled. */
132 MULTI_STOP_PREPARE,
133 /* Disable interrupts. */
134 MULTI_STOP_DISABLE_IRQ,
135 /* Run the function */
136 MULTI_STOP_RUN,
137 /* Exit */
138 MULTI_STOP_EXIT,
139};
140
141struct multi_stop_data {
142 int (*fn)(void *);
143 void *data;
144 /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
145 unsigned int num_threads;
146 const struct cpumask *active_cpus;
147
148 enum multi_stop_state state;
149 atomic_t thread_ack;
150};
151
152static void set_state(struct multi_stop_data *msdata,
153 enum multi_stop_state newstate)
154{
155 /* Reset ack counter. */
156 atomic_set(&msdata->thread_ack, msdata->num_threads);
157 smp_wmb();
158 msdata->state = newstate;
159}
160
161/* Last one to ack a state moves to the next state. */
162static void ack_state(struct multi_stop_data *msdata)
163{
164 if (atomic_dec_and_test(&msdata->thread_ack))
165 set_state(msdata, msdata->state + 1);
166}
167
168/* This is the cpu_stop function which stops the CPU. */
169static int multi_cpu_stop(void *data)
170{
171 struct multi_stop_data *msdata = data;
172 enum multi_stop_state curstate = MULTI_STOP_NONE;
173 int cpu = smp_processor_id(), err = 0;
174 unsigned long flags;
175 bool is_active;
176
177 /*
178 * When called from stop_machine_from_inactive_cpu(), irq might
179 * already be disabled. Save the state and restore it on exit.
180 */
181 local_save_flags(flags);
182
183 if (!msdata->active_cpus)
184 is_active = cpu == cpumask_first(cpu_online_mask);
185 else
186 is_active = cpumask_test_cpu(cpu, msdata->active_cpus);
187
188 /* Simple state machine */
189 do {
190 /* Chill out and ensure we re-read multi_stop_state. */
191 cpu_relax();
192 if (msdata->state != curstate) {
193 curstate = msdata->state;
194 switch (curstate) {
195 case MULTI_STOP_DISABLE_IRQ:
196 local_irq_disable();
197 hard_irq_disable();
198 break;
199 case MULTI_STOP_RUN:
200 if (is_active)
201 err = msdata->fn(msdata->data);
202 break;
203 default:
204 break;
205 }
206 ack_state(msdata);
207 }
208 } while (curstate != MULTI_STOP_EXIT);
209
210 local_irq_restore(flags);
211 return err;
212}
213
214struct irq_cpu_stop_queue_work_info {
215 int cpu1;
216 int cpu2;
217 struct cpu_stop_work *work1;
218 struct cpu_stop_work *work2;
219};
220
221/*
222 * This function is always run with irqs and preemption disabled.
223 * This guarantees that both work1 and work2 get queued, before
224 * our local migrate thread gets the chance to preempt us.
225 */
226static void irq_cpu_stop_queue_work(void *arg)
227{
228 struct irq_cpu_stop_queue_work_info *info = arg;
229 cpu_stop_queue_work(info->cpu1, info->work1);
230 cpu_stop_queue_work(info->cpu2, info->work2);
231}
232
233/**
234 * stop_two_cpus - stops two cpus
235 * @cpu1: the cpu to stop
236 * @cpu2: the other cpu to stop
237 * @fn: function to execute
238 * @arg: argument to @fn
239 *
240 * Stops both the current and specified CPU and runs @fn on one of them.
241 *
242 * returns when both are completed.
243 */
244int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg)
245{
246 struct cpu_stop_done done;
247 struct cpu_stop_work work1, work2;
248 struct irq_cpu_stop_queue_work_info call_args;
249 struct multi_stop_data msdata;
250
251 preempt_disable();
252 msdata = (struct multi_stop_data){
253 .fn = fn,
254 .data = arg,
255 .num_threads = 2,
256 .active_cpus = cpumask_of(cpu1),
257 };
258
259 work1 = work2 = (struct cpu_stop_work){
260 .fn = multi_cpu_stop,
261 .arg = &msdata,
262 .done = &done
263 };
264
265 call_args = (struct irq_cpu_stop_queue_work_info){
266 .cpu1 = cpu1,
267 .cpu2 = cpu2,
268 .work1 = &work1,
269 .work2 = &work2,
270 };
271
272 cpu_stop_init_done(&done, 2);
273 set_state(&msdata, MULTI_STOP_PREPARE);
274
275 /*
276 * If we observe both CPUs active we know _cpu_down() cannot yet have
277 * queued its stop_machine works and therefore ours will get executed
278 * first. Or its not either one of our CPUs that's getting unplugged,
279 * in which case we don't care.
280 *
281 * This relies on the stopper workqueues to be FIFO.
282 */
283 if (!cpu_active(cpu1) || !cpu_active(cpu2)) {
284 preempt_enable();
285 return -ENOENT;
286 }
287
288 lg_local_lock(&stop_cpus_lock);
289 /*
290 * Queuing needs to be done by the lowest numbered CPU, to ensure
291 * that works are always queued in the same order on every CPU.
292 * This prevents deadlocks.
293 */
294 smp_call_function_single(min(cpu1, cpu2),
295 &irq_cpu_stop_queue_work,
296 &call_args, 0);
297 lg_local_unlock(&stop_cpus_lock);
298 preempt_enable();
299
300 wait_for_completion(&done.completion);
301
302 return done.executed ? done.ret : -ENOENT;
303}
304
118/** 305/**
119 * stop_one_cpu_nowait - stop a cpu but don't wait for completion 306 * stop_one_cpu_nowait - stop a cpu but don't wait for completion
120 * @cpu: cpu to stop 307 * @cpu: cpu to stop
@@ -159,10 +346,10 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
159 * preempted by a stopper which might wait for other stoppers 346 * preempted by a stopper which might wait for other stoppers
160 * to enter @fn which can lead to deadlock. 347 * to enter @fn which can lead to deadlock.
161 */ 348 */
162 preempt_disable(); 349 lg_global_lock(&stop_cpus_lock);
163 for_each_cpu(cpu, cpumask) 350 for_each_cpu(cpu, cpumask)
164 cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu)); 351 cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
165 preempt_enable(); 352 lg_global_unlock(&stop_cpus_lock);
166} 353}
167 354
168static int __stop_cpus(const struct cpumask *cpumask, 355static int __stop_cpus(const struct cpumask *cpumask,
@@ -359,98 +546,14 @@ early_initcall(cpu_stop_init);
359 546
360#ifdef CONFIG_STOP_MACHINE 547#ifdef CONFIG_STOP_MACHINE
361 548
362/* This controls the threads on each CPU. */
363enum stopmachine_state {
364 /* Dummy starting state for thread. */
365 STOPMACHINE_NONE,
366 /* Awaiting everyone to be scheduled. */
367 STOPMACHINE_PREPARE,
368 /* Disable interrupts. */
369 STOPMACHINE_DISABLE_IRQ,
370 /* Run the function */
371 STOPMACHINE_RUN,
372 /* Exit */
373 STOPMACHINE_EXIT,
374};
375
376struct stop_machine_data {
377 int (*fn)(void *);
378 void *data;
379 /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
380 unsigned int num_threads;
381 const struct cpumask *active_cpus;
382
383 enum stopmachine_state state;
384 atomic_t thread_ack;
385};
386
387static void set_state(struct stop_machine_data *smdata,
388 enum stopmachine_state newstate)
389{
390 /* Reset ack counter. */
391 atomic_set(&smdata->thread_ack, smdata->num_threads);
392 smp_wmb();
393 smdata->state = newstate;
394}
395
396/* Last one to ack a state moves to the next state. */
397static void ack_state(struct stop_machine_data *smdata)
398{
399 if (atomic_dec_and_test(&smdata->thread_ack))
400 set_state(smdata, smdata->state + 1);
401}
402
403/* This is the cpu_stop function which stops the CPU. */
404static int stop_machine_cpu_stop(void *data)
405{
406 struct stop_machine_data *smdata = data;
407 enum stopmachine_state curstate = STOPMACHINE_NONE;
408 int cpu = smp_processor_id(), err = 0;
409 unsigned long flags;
410 bool is_active;
411
412 /*
413 * When called from stop_machine_from_inactive_cpu(), irq might
414 * already be disabled. Save the state and restore it on exit.
415 */
416 local_save_flags(flags);
417
418 if (!smdata->active_cpus)
419 is_active = cpu == cpumask_first(cpu_online_mask);
420 else
421 is_active = cpumask_test_cpu(cpu, smdata->active_cpus);
422
423 /* Simple state machine */
424 do {
425 /* Chill out and ensure we re-read stopmachine_state. */
426 cpu_relax();
427 if (smdata->state != curstate) {
428 curstate = smdata->state;
429 switch (curstate) {
430 case STOPMACHINE_DISABLE_IRQ:
431 local_irq_disable();
432 hard_irq_disable();
433 break;
434 case STOPMACHINE_RUN:
435 if (is_active)
436 err = smdata->fn(smdata->data);
437 break;
438 default:
439 break;
440 }
441 ack_state(smdata);
442 }
443 } while (curstate != STOPMACHINE_EXIT);
444
445 local_irq_restore(flags);
446 return err;
447}
448
449int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) 549int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
450{ 550{
451 struct stop_machine_data smdata = { .fn = fn, .data = data, 551 struct multi_stop_data msdata = {
452 .num_threads = num_online_cpus(), 552 .fn = fn,
453 .active_cpus = cpus }; 553 .data = data,
554 .num_threads = num_online_cpus(),
555 .active_cpus = cpus,
556 };
454 557
455 if (!stop_machine_initialized) { 558 if (!stop_machine_initialized) {
456 /* 559 /*
@@ -461,7 +564,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
461 unsigned long flags; 564 unsigned long flags;
462 int ret; 565 int ret;
463 566
464 WARN_ON_ONCE(smdata.num_threads != 1); 567 WARN_ON_ONCE(msdata.num_threads != 1);
465 568
466 local_irq_save(flags); 569 local_irq_save(flags);
467 hard_irq_disable(); 570 hard_irq_disable();
@@ -472,8 +575,8 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
472 } 575 }
473 576
474 /* Set the initial state and stop all online cpus. */ 577 /* Set the initial state and stop all online cpus. */
475 set_state(&smdata, STOPMACHINE_PREPARE); 578 set_state(&msdata, MULTI_STOP_PREPARE);
476 return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata); 579 return stop_cpus(cpu_online_mask, multi_cpu_stop, &msdata);
477} 580}
478 581
479int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) 582int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
@@ -513,25 +616,25 @@ EXPORT_SYMBOL_GPL(stop_machine);
513int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data, 616int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data,
514 const struct cpumask *cpus) 617 const struct cpumask *cpus)
515{ 618{
516 struct stop_machine_data smdata = { .fn = fn, .data = data, 619 struct multi_stop_data msdata = { .fn = fn, .data = data,
517 .active_cpus = cpus }; 620 .active_cpus = cpus };
518 struct cpu_stop_done done; 621 struct cpu_stop_done done;
519 int ret; 622 int ret;
520 623
521 /* Local CPU must be inactive and CPU hotplug in progress. */ 624 /* Local CPU must be inactive and CPU hotplug in progress. */
522 BUG_ON(cpu_active(raw_smp_processor_id())); 625 BUG_ON(cpu_active(raw_smp_processor_id()));
523 smdata.num_threads = num_active_cpus() + 1; /* +1 for local */ 626 msdata.num_threads = num_active_cpus() + 1; /* +1 for local */
524 627
525 /* No proper task established and can't sleep - busy wait for lock. */ 628 /* No proper task established and can't sleep - busy wait for lock. */
526 while (!mutex_trylock(&stop_cpus_mutex)) 629 while (!mutex_trylock(&stop_cpus_mutex))
527 cpu_relax(); 630 cpu_relax();
528 631
529 /* Schedule work on other CPUs and execute directly for local CPU */ 632 /* Schedule work on other CPUs and execute directly for local CPU */
530 set_state(&smdata, STOPMACHINE_PREPARE); 633 set_state(&msdata, MULTI_STOP_PREPARE);
531 cpu_stop_init_done(&done, num_active_cpus()); 634 cpu_stop_init_done(&done, num_active_cpus());
532 queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata, 635 queue_stop_cpus_work(cpu_active_mask, multi_cpu_stop, &msdata,
533 &done); 636 &done);
534 ret = stop_machine_cpu_stop(&smdata); 637 ret = multi_cpu_stop(&msdata);
535 638
536 /* Busy wait for completion. */ 639 /* Busy wait for completion. */
537 while (!completion_done(&done.completion)) 640 while (!completion_done(&done.completion))
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 5fee859888a4..36547dddcdb8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -371,13 +371,6 @@ static struct ctl_table kern_table[] = {
371 .proc_handler = proc_dointvec, 371 .proc_handler = proc_dointvec,
372 }, 372 },
373 { 373 {
374 .procname = "numa_balancing_scan_period_reset",
375 .data = &sysctl_numa_balancing_scan_period_reset,
376 .maxlen = sizeof(unsigned int),
377 .mode = 0644,
378 .proc_handler = proc_dointvec,
379 },
380 {
381 .procname = "numa_balancing_scan_period_max_ms", 374 .procname = "numa_balancing_scan_period_max_ms",
382 .data = &sysctl_numa_balancing_scan_period_max, 375 .data = &sysctl_numa_balancing_scan_period_max,
383 .maxlen = sizeof(unsigned int), 376 .maxlen = sizeof(unsigned int),
@@ -391,6 +384,20 @@ static struct ctl_table kern_table[] = {
391 .mode = 0644, 384 .mode = 0644,
392 .proc_handler = proc_dointvec, 385 .proc_handler = proc_dointvec,
393 }, 386 },
387 {
388 .procname = "numa_balancing_settle_count",
389 .data = &sysctl_numa_balancing_settle_count,
390 .maxlen = sizeof(unsigned int),
391 .mode = 0644,
392 .proc_handler = proc_dointvec,
393 },
394 {
395 .procname = "numa_balancing_migrate_deferred",
396 .data = &sysctl_numa_balancing_migrate_deferred,
397 .maxlen = sizeof(unsigned int),
398 .mode = 0644,
399 .proc_handler = proc_dointvec,
400 },
394#endif /* CONFIG_NUMA_BALANCING */ 401#endif /* CONFIG_NUMA_BALANCING */
395#endif /* CONFIG_SCHED_DEBUG */ 402#endif /* CONFIG_SCHED_DEBUG */
396 { 403 {
diff --git a/kernel/timer.c b/kernel/timer.c
index 4296d13db3d1..6582b82fa966 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1092,7 +1092,7 @@ static int cascade(struct tvec_base *base, struct tvec *tv, int index)
1092static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long), 1092static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
1093 unsigned long data) 1093 unsigned long data)
1094{ 1094{
1095 int preempt_count = preempt_count(); 1095 int count = preempt_count();
1096 1096
1097#ifdef CONFIG_LOCKDEP 1097#ifdef CONFIG_LOCKDEP
1098 /* 1098 /*
@@ -1119,16 +1119,16 @@ static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
1119 1119
1120 lock_map_release(&lockdep_map); 1120 lock_map_release(&lockdep_map);
1121 1121
1122 if (preempt_count != preempt_count()) { 1122 if (count != preempt_count()) {
1123 WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n", 1123 WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n",
1124 fn, preempt_count, preempt_count()); 1124 fn, count, preempt_count());
1125 /* 1125 /*
1126 * Restore the preempt count. That gives us a decent 1126 * Restore the preempt count. That gives us a decent
1127 * chance to survive and extract information. If the 1127 * chance to survive and extract information. If the
1128 * callback kept a lock held, bad luck, but not worse 1128 * callback kept a lock held, bad luck, but not worse
1129 * than the BUG() we had. 1129 * than the BUG() we had.
1130 */ 1130 */
1131 preempt_count() = preempt_count; 1131 preempt_count_set(count);
1132 } 1132 }
1133} 1133}
1134 1134
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7974ba20557d..d9fea7dfd5d3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1509,7 +1509,8 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
1509#endif 1509#endif
1510 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | 1510 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
1511 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | 1511 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
1512 (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); 1512 (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
1513 (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
1513} 1514}
1514EXPORT_SYMBOL_GPL(tracing_generic_entry_update); 1515EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
1515 1516
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 10c86fb7a2b4..73d08aa25b55 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -124,6 +124,7 @@ enum trace_flag_type {
124 TRACE_FLAG_NEED_RESCHED = 0x04, 124 TRACE_FLAG_NEED_RESCHED = 0x04,
125 TRACE_FLAG_HARDIRQ = 0x08, 125 TRACE_FLAG_HARDIRQ = 0x08,
126 TRACE_FLAG_SOFTIRQ = 0x10, 126 TRACE_FLAG_SOFTIRQ = 0x10,
127 TRACE_FLAG_PREEMPT_RESCHED = 0x20,
127}; 128};
128 129
129#define TRACE_BUF_SIZE 1024 130#define TRACE_BUF_SIZE 1024
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 34e7cbac0c9c..ed32284fbe32 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -618,8 +618,23 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
618 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : 618 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
619 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : 619 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
620 '.'; 620 '.';
621 need_resched = 621
622 (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'; 622 switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
623 TRACE_FLAG_PREEMPT_RESCHED)) {
624 case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
625 need_resched = 'N';
626 break;
627 case TRACE_FLAG_NEED_RESCHED:
628 need_resched = 'n';
629 break;
630 case TRACE_FLAG_PREEMPT_RESCHED:
631 need_resched = 'p';
632 break;
633 default:
634 need_resched = '.';
635 break;
636 }
637
623 hardsoft_irq = 638 hardsoft_irq =
624 (hardirq && softirq) ? 'H' : 639 (hardirq && softirq) ? 'H' :
625 hardirq ? 'h' : 640 hardirq ? 'h' :
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-03 21:20:31 -0500