diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 10:50:17 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 10:50:17 -0400 |
commit | 8700c95adb033843fc163d112b9d21d4fda78018 (patch) | |
tree | 7bb9a37b8fe6328f63a61d88063c556346001098 /arch/sh/kernel | |
parent | 16fa94b532b1958f508e07eca1a9256351241fbc (diff) | |
parent | d190e8195b90bc1e65c494fe08e54e9e581bfd16 (diff) |
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
"This is a pretty large, multi-arch series unifying and generalizing
the various disjunct pieces of idle routines that architectures have
historically copied from each other and have grown in random, wildly
inconsistent and sometimes buggy directions:
101 files changed, 455 insertions(+), 1328 deletions(-)
this went through a number of review and test iterations before it was
committed, it was tested on various architectures, was exposed to
linux-next for quite some time - nevertheless it might cause problems
on architectures that don't read the mailing lists and don't regularly
test linux-next.
This cat herding excercise was motivated by the -rt kernel, and was
brought to you by Thomas "the Whip" Gleixner."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
idle: Remove GENERIC_IDLE_LOOP config switch
um: Use generic idle loop
ia64: Make sure interrupts enabled when we "safe_halt()"
sparc: Use generic idle loop
idle: Remove unused ARCH_HAS_DEFAULT_IDLE
bfin: Fix typo in arch_cpu_idle()
xtensa: Use generic idle loop
x86: Use generic idle loop
unicore: Use generic idle loop
tile: Use generic idle loop
tile: Enter idle with preemption disabled
sh: Use generic idle loop
score: Use generic idle loop
s390: Use generic idle loop
powerpc: Use generic idle loop
parisc: Use generic idle loop
openrisc: Use generic idle loop
mn10300: Use generic idle loop
mips: Use generic idle loop
microblaze: Use generic idle loop
...
Diffstat (limited to 'arch/sh/kernel')
-rw-r--r-- | arch/sh/kernel/idle.c | 101 | ||||
-rw-r--r-- | arch/sh/kernel/smp.c | 2 |
2 files changed, 12 insertions, 91 deletions
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c index 3d5a1b387cc0..2ea4483fd722 100644 --- a/arch/sh/kernel/idle.c +++ b/arch/sh/kernel/idle.c | |||
@@ -24,98 +24,24 @@ | |||
24 | 24 | ||
25 | static void (*sh_idle)(void); | 25 | static void (*sh_idle)(void); |
26 | 26 | ||
27 | static int hlt_counter; | 27 | void default_idle(void) |
28 | |||
29 | static int __init nohlt_setup(char *__unused) | ||
30 | { | ||
31 | hlt_counter = 1; | ||
32 | return 1; | ||
33 | } | ||
34 | __setup("nohlt", nohlt_setup); | ||
35 | |||
36 | static int __init hlt_setup(char *__unused) | ||
37 | { | ||
38 | hlt_counter = 0; | ||
39 | return 1; | ||
40 | } | ||
41 | __setup("hlt", hlt_setup); | ||
42 | |||
43 | static inline int hlt_works(void) | ||
44 | { | ||
45 | return !hlt_counter; | ||
46 | } | ||
47 | |||
48 | /* | ||
49 | * On SMP it's slightly faster (but much more power-consuming!) | ||
50 | * to poll the ->work.need_resched flag instead of waiting for the | ||
51 | * cross-CPU IPI to arrive. Use this option with caution. | ||
52 | */ | ||
53 | static void poll_idle(void) | ||
54 | { | 28 | { |
29 | set_bl_bit(); | ||
55 | local_irq_enable(); | 30 | local_irq_enable(); |
56 | while (!need_resched()) | 31 | /* Isn't this racy ? */ |
57 | cpu_relax(); | 32 | cpu_sleep(); |
33 | clear_bl_bit(); | ||
58 | } | 34 | } |
59 | 35 | ||
60 | void default_idle(void) | 36 | void arch_cpu_idle_dead(void) |
61 | { | 37 | { |
62 | if (hlt_works()) { | 38 | play_dead(); |
63 | clear_thread_flag(TIF_POLLING_NRFLAG); | ||
64 | smp_mb__after_clear_bit(); | ||
65 | |||
66 | set_bl_bit(); | ||
67 | if (!need_resched()) { | ||
68 | local_irq_enable(); | ||
69 | cpu_sleep(); | ||
70 | } else | ||
71 | local_irq_enable(); | ||
72 | |||
73 | set_thread_flag(TIF_POLLING_NRFLAG); | ||
74 | clear_bl_bit(); | ||
75 | } else | ||
76 | poll_idle(); | ||
77 | } | 39 | } |
78 | 40 | ||
79 | /* | 41 | void arch_cpu_idle(void) |
80 | * The idle thread. There's no useful work to be done, so just try to conserve | ||
81 | * power and have a low exit latency (ie sit in a loop waiting for somebody to | ||
82 | * say that they'd like to reschedule) | ||
83 | */ | ||
84 | void cpu_idle(void) | ||
85 | { | 42 | { |
86 | unsigned int cpu = smp_processor_id(); | 43 | if (cpuidle_idle_call()) |
87 | 44 | sh_idle(); | |
88 | set_thread_flag(TIF_POLLING_NRFLAG); | ||
89 | |||
90 | /* endless idle loop with no priority at all */ | ||
91 | while (1) { | ||
92 | tick_nohz_idle_enter(); | ||
93 | rcu_idle_enter(); | ||
94 | |||
95 | while (!need_resched()) { | ||
96 | check_pgt_cache(); | ||
97 | rmb(); | ||
98 | |||
99 | if (cpu_is_offline(cpu)) | ||
100 | play_dead(); | ||
101 | |||
102 | local_irq_disable(); | ||
103 | /* Don't trace irqs off for idle */ | ||
104 | stop_critical_timings(); | ||
105 | if (cpuidle_idle_call()) | ||
106 | sh_idle(); | ||
107 | /* | ||
108 | * Sanity check to ensure that sh_idle() returns | ||
109 | * with IRQs enabled | ||
110 | */ | ||
111 | WARN_ON(irqs_disabled()); | ||
112 | start_critical_timings(); | ||
113 | } | ||
114 | |||
115 | rcu_idle_exit(); | ||
116 | tick_nohz_idle_exit(); | ||
117 | schedule_preempt_disabled(); | ||
118 | } | ||
119 | } | 45 | } |
120 | 46 | ||
121 | void __init select_idle_routine(void) | 47 | void __init select_idle_routine(void) |
@@ -123,13 +49,8 @@ void __init select_idle_routine(void) | |||
123 | /* | 49 | /* |
124 | * If a platform has set its own idle routine, leave it alone. | 50 | * If a platform has set its own idle routine, leave it alone. |
125 | */ | 51 | */ |
126 | if (sh_idle) | 52 | if (!sh_idle) |
127 | return; | ||
128 | |||
129 | if (hlt_works()) | ||
130 | sh_idle = default_idle; | 53 | sh_idle = default_idle; |
131 | else | ||
132 | sh_idle = poll_idle; | ||
133 | } | 54 | } |
134 | 55 | ||
135 | void stop_this_cpu(void *unused) | 56 | void stop_this_cpu(void *unused) |
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 2062aa88af41..45696451f0ea 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c | |||
@@ -203,7 +203,7 @@ asmlinkage void __cpuinit start_secondary(void) | |||
203 | set_cpu_online(cpu, true); | 203 | set_cpu_online(cpu, true); |
204 | per_cpu(cpu_state, cpu) = CPU_ONLINE; | 204 | per_cpu(cpu_state, cpu) = CPU_ONLINE; |
205 | 205 | ||
206 | cpu_idle(); | 206 | cpu_startup_entry(CPUHP_ONLINE); |
207 | } | 207 | } |
208 | 208 | ||
209 | extern struct { | 209 | extern struct { |