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* | sched/idle: Remove stale old filePeter Zijlstra2014-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit cf37b6b48428d ("sched/idle: Move cpu/idle.c to sched/idle.c") said to simply move a file; somehow it got mangled and created an old version of the file and forgot to remove the old file. Fix this fail; add the lost change and remove the now identical old file. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: rjw@rjwysocki.net Cc: nicolas.pitre@linaro.org Cc: preeti@linux.vnet.ibm.com Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Link: http://lkml.kernel.org/r/20140224172207.GC9987@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHEDDietmar Eggemann2014-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The struct sched_avg of struct rq is only used in case group scheduling is enabled inside __update_tg_runnable_avg() to update per-cpu representation of a task group. I.e. that there is no need to maintain the runnable avg of a rq in the !CONFIG_FAIR_GROUP_SCHED case. This patch guards struct sched_avg of struct rq and update_rq_runnable_avg() with CONFIG_FAIR_GROUP_SCHED. There is an extra empty definition for update_rq_runnable_avg() necessary for the !CONFIG_FAIR_GROUP_SCHED && CONFIG_SMP case. The function print_cfs_group_stats() which prints out struct sched_avg of struct rq is already guarded with CONFIG_FAIR_GROUP_SCHED. Reviewed-by: Ben Segall <bsegall@google.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/530DCDC5.1060406@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched, nohz: Exclude isolated cores from load balancingMike Galbraith2014-02-22
| | | | | | | | | | | | | | | | | | | | | | | | The user explicitly disabled load balancing, else this core would not be disconnected. Don't add these to nohz.idle_cpus_mask. Signed-off-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Lei Wen <leiwen@marvell.com> Link: http://lkml.kernel.org/n/tip-vmme4f49psirp966pklm5l9j@git.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Fix select_task_rq_fair() description commentsMorten Rasmussen2014-02-22
| | | | | | | | | | | | | | | | | | | | Brings select_task_rq_fair() description comments up-to-date. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1392732864-10927-1-git-send-email-morten.rasmussen@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICEDongsheng Yang2014-02-22
| | | | | | | | | | | | | | | | Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/bd80780f19b4f9b4a765acc353c8dbc130274dd6.1392103744.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/rt: Make init_sched_rt_calss() __initLi Zefan2014-02-22
| | | | | | | | | | | | | | | | | | | | It's a bootstrap function. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/52F5CC09.1080502@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/rt: Remove 'leaf_rt_rq_list' from 'struct rq'Li Zefan2014-02-22
| | | | | | | | | | | | | | | | | | | | | | This is a leftover from commit e23ee74777f389369431d77390c4b09332ce026a ("sched/rt: Simplify pull_rt_task() logic and remove .leaf_rt_rq_list"). Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/52F5CBF6.4060901@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Consider pi boosting in setscheduler()Thomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a PI boosted task policy/priority is modified by a setscheduler() call we unconditionally dequeue and requeue the task if it is on the runqueue even if the new priority is lower than the current effective boosted priority. This can result in undesired reordering of the priority bucket list. If the new priority is less or equal than the current effective we just store the new parameters in the task struct and leave the scheduler class and the runqueue untouched. This is handled when the task deboosts itself. Only if the new priority is higher than the effective boosted priority we apply the change immediately. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebase ontop of v3.14-rc1. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Dario Faggioli <raistlin@linux.it> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-7-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Queue RT tasks to head when prio dropsThomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following scenario does not work correctly: Runqueue of CPUx contains two runnable and pinned tasks: T1: SCHED_FIFO, prio 80 T2: SCHED_FIFO, prio 80 T1 is on the cpu and executes the following syscalls (classic priority ceiling scenario): sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 90); ... sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 80); ... Now T1 gets preempted by T3 (SCHED_FIFO, prio 95). After T3 goes back to sleep the scheduler picks T2. Surprise! The same happens w/o actual preemption when T1 is forced into the scheduler due to a sporadic NEED_RESCHED event. The scheduler invokes pick_next_task() which returns T2. So T1 gets preempted and scheduled out. This happens because sched_setscheduler() dequeues T1 from the prio 90 list and then enqueues it on the tail of the prio 80 list behind T2. This violates the POSIX spec and surprises user space which relies on the guarantee that SCHED_FIFO tasks are not scheduled out unless they give the CPU up voluntarily or are preempted by a higher priority task. In the latter case the preempted task must get back on the CPU after the preempting task schedules out again. We fixed a similar issue already in commit 60db48c (sched: Queue a deboosted task to the head of the RT prio queue). The same treatment is necessary for sched_setscheduler(). So enqueue to head of the prio bucket list if the priority of the task is lowered. It might be possible that existing user space relies on the current behaviour, but it can be considered highly unlikely due to the corner case nature of the application scenario. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-6-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Adjust p->sched_reset_on_fork when nothing else changesThomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | | | | | If the policy and priority remain unchanged a possible modification of p->sched_reset_on_fork gets lost in the early exit path. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebase ontop of v3.14-rc1. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-5-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Add better debug output for might_sleep()Thomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | | | might_sleep() can tell us where interrupts have been disabled, but we have no idea what disabled preemption. Add some debug infrastructure. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-4-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Check for idle task in might_sleep()Thomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | Idle is not allowed to call sleeping functions ever! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-3-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Init idle->on_rq in init_idle()Thomas Gleixner2014-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We stumbled in RT over a SMP bringup issue on ARM where the idle->on_rq == 0 was causing try_to_wakeup() on the other cpu to run into nada land. After adding that idle->on_rq = 1; I was able to find the root cause of the lockup: the idle task on the newly woken up cpu was fiddling with a sleeping spinlock, which is a nono. I kept the init of idle->on_rq to keep the state consistent and to avoid another long lasting debug session. As a side note, the whole debug mess could have been avoided if might_sleep() would have yelled when called from the idle task. That's fixed with patch 2/6 - and that one actually has a changelog :) Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391803122-4425-2-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Remove some #ifdefferyPeter Zijlstra2014-02-21
| | | | | | | | | | | | | | | | | | | | | | Remove a few gratuitous #ifdefs in pick_next_task*(). Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-nnzddp5c4fijyzzxxrwlxghf@git.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | sched: Fix hotplug task migrationPeter Zijlstra2014-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dan Carpenter reported: > kernel/sched/rt.c:1347 pick_next_task_rt() warn: variable dereferenced before check 'prev' (see line 1338) > kernel/sched/deadline.c:1011 pick_next_task_dl() warn: variable dereferenced before check 'prev' (see line 1005) Kirill also spotted that migrate_tasks() will have an instant NULL deref because pick_next_task() will immediately deref prev. Instead of fixing all the corner cases because migrate_tasks() can pass in a NULL prev task in the unlikely case of hot-un-plug, provide a fake task such that we can remove all the NULL checks from the far more common paths. A further problem; not previously spotted; is that because we pushed pre_schedule() and idle_balance() into pick_next_task() we now need to avoid those getting called and pulling more tasks on our dying CPU. We avoid pull_{dl,rt}_task() by setting fake_task.prio to MAX_PRIO+1. We also note that since we call pick_next_task() exactly the amount of times we have runnable tasks present, we should never land in idle_balance(). Fixes: 38033c37faab ("sched: Push down pre_schedule() and idle_balance()") Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Reported-by: Kirill Tkhai <tkhai@yandex.ru> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140212094930.GB3545@laptop.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | sched/fair: Remove idle_balance() declaration in sched.hPeter Zijlstra2014-02-21
| | | | | | | | | | | | | | | | | | | | | | | | Remove idle_balance() from the public life; also reduce some #ifdef clutter by folding the pick_next_task_fair() idle path into idle_balance(). Cc: mingo@kernel.org Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140211151148.GP27965@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | sched/fair: Reset se-depth when task switched to FAIRMichael wang2014-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha reported: [ 522.645288] BUG: unable to handle kernel NULL pointer dereference at ... [ 522.646271] IP: [<ffffffff81186c6f>] check_preempt_wakeup+0x11f/0x210 ... [ 522.650021] Call Trace: [ 522.650021] <IRQ> [ 522.650021] [<ffffffff8117361d>] check_preempt_curr+0x3d/0xb0 [ 522.650021] [<ffffffff81175d88>] ttwu_do_wakeup+0x18/0x130 ... which was caused by the se-depth changed during the time when task is not FAIR, and we will use the wrong depth value after it switched back to FAIR. This patch reset the depth at the time when task switched to FAIR, make sure that we always have the correct value when task is FAIR. Cc: Ingo Molnar <mingo@kernel.org> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5305732D.70001@linux.vnet.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | sched/idle: Move cpu/idle.c to sched/idle.cNicolas Pitre2014-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Integration of cpuidle with the scheduler requires that the idle loop be closely integrated with the scheduler proper. Moving cpu/idle.c into the sched directory will allow for a smoother integration, and eliminate a subdirectory which contained only one source file. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.LFD.2.11.1401301102210.1652@knanqh.ubzr Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Add statistic for newidle load balance costAlex Shi2014-02-11
| | | | | | | | | | | | | | | | | | | | Tracking rq->max_idle_balance_cost and sd->max_newidle_lb_cost. It's useful to know these values in debug mode. Signed-off-by: Alex Shi <alex.shi@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/52E0F3BF.5020904@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Delete is_same_group() outside CONFIG_FAIR_GROUP_SCHEDDietmar Eggemann2014-02-11
| | | | | | | | | | | | | | | | | | | | Since is_same_group() is only used in the group scheduling code, there is no need to define it outside CONFIG_FAIR_GROUP_SCHED. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1391005773-29493-1-git-send-email-dietmar.eggemann@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Push down pre_schedule() and idle_balance()Peter Zijlstra2014-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch both merged idle_balance() and pre_schedule() and pushes both of them into pick_next_task(). Conceptually pre_schedule() and idle_balance() are rather similar, both are used to pull more work onto the current CPU. We cannot however first move idle_balance() into pre_schedule_fair() since there is no guarantee the last runnable task is a fair task, and thus we would miss newidle balances. Similarly, the dl and rt pre_schedule calls must be ran before idle_balance() since their respective tasks have higher priority and it would not do to delay their execution searching for less important tasks first. However, by noticing that pick_next_tasks() already traverses the sched_class hierarchy in the right order, we can get the right behaviour and do away with both calls. We must however change the special case optimization to also require that prev is of sched_class_fair, otherwise we can miss doing a dl or rt pull where we needed one. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/n/tip-a8k6vvaebtn64nie345kx1je@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Clean up idle task SMP logicPeter Zijlstra2014-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idle post_schedule flag is just a vile waste of time, furthermore it appears unneeded, move the idle_enter_fair() call into pick_next_task_idle(). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: alex.shi@linaro.org Cc: mingo@kernel.org Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/n/tip-aljykihtxJt3mkokxi0qZurb@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/fair: Optimize cgroup pick_next_task_fair()Peter Zijlstra2014-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 2f36825b1 ("sched: Next buddy hint on sleep and preempt path") it is likely we pick a new task from the same cgroup, doing a put and then set on all intermediate entities is a waste of time, so try to avoid this. Measured using: mount nodev /cgroup -t cgroup -o cpu cd /cgroup mkdir a; cd a mkdir b; cd b mkdir c; cd c echo $$ > tasks perf stat --repeat 10 -- taskset 1 perf bench sched pipe PRE : 4.542422684 seconds time elapsed ( +- 0.33% ) POST: 4.389409991 seconds time elapsed ( +- 0.32% ) Which shows a significant improvement of ~3.5% Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/fair: Clean up the __clear_buddies_*() functionsPeter Zijlstra2014-02-10
| | | | | | | | | | | | | | | | Slightly easier code flow, no functional changes. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Push put_prev_task() into pick_next_task()Peter Zijlstra2014-02-10
| | | | | | | | | | | | | | | | | | | | | | In order to avoid having to do put/set on a whole cgroup hierarchy when we context switch, push the put into pick_next_task() so that both operations are in the same function. Further changes then allow us to possibly optimize away redundant work. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/fair: Track cgroup depthPeter Zijlstra2014-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Track depth in cgroup tree, this is useful for things like find_matching_se() where you need to get to a common parent of two sched entities. Keeping the depth avoids having to calculate it on the spot, which saves a number of possible cache-misses. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Move rq->idle_stamp up to the coreDaniel Lezcano2014-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | idle_balance() modifies the rq->idle_stamp field, making this information shared across core.c and fair.c. As we know if the cpu is going to idle or not with the previous patch, let's encapsulate the rq->idle_stamp information in core.c by moving it up to the caller. The idle_balance() function returns true in case a balancing occured and the cpu won't be idle, false if no balance happened and the cpu is going idle. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: alex.shi@linaro.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389949444-14821-3-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Fix race in idle_balance()Daniel Lezcano2014-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The scheduler main function 'schedule()' checks if there are no more tasks on the runqueue. Then it checks if a task should be pulled in the current runqueue in idle_balance() assuming it will go to idle otherwise. But idle_balance() releases the rq->lock in order to look up the sched domains and takes the lock again right after. That opens a window where another cpu may put a task in our runqueue, so we won't go to idle but we have filled the idle_stamp, thinking we will. This patch closes the window by checking if the runqueue has been modified but without pulling a task after taking the lock again, so we won't go to idle right after in the __schedule() function. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: alex.shi@linaro.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389949444-14821-2-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Remove 'cpu' parameter from idle_balance()Daniel Lezcano2014-02-10
| | | | | | | | | | | | | | | | | | | | | | The cpu parameter passed to idle_balance() is not needed as it could be retrieved from 'struct rq.' Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: alex.shi@linaro.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389949444-14821-1-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Implement task_nice() as static inline functionDongsheng Yang2014-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As patch "sched: Move the priority specific bits into a new header file" exposes the priority related macros in linux/sched/prio.h, we don't have to implement task_nice() in kernel/sched/core.c any more. This patch implements it in linux/sched/sched.h as static inline function, saving the kernel stack and enhancing performance a bit. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: clark.williams@gmail.com Cc: rostedt@goodmis.org Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1390878045-7096-1-git-send-email-yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Expose some macros related to priorityDongsheng Yang2014-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some macros in kernel/sched/sched.h about priority are private to kernel/sched. But they are useful to other parts of the core kernel. This patch moves these macros from kernel/sched/sched.h to include/linux/sched/prio.h so that they are available to other subsystems. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Cc: clark.williams@gmail.com Cc: rostedt@goodmis.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2b022810905b52d13238466807f4b2a691577180.1390859827.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/deadline: Skip in switched_to_dl() if task is currentKirill Tkhai2014-02-09
| | | | | | | | | | | | | | | | | | | | | | | | When p is current and it's not of dl class, then there are no other dl taks in the rq. If we had had pushable tasks in some other rq, they would have been pushed earlier. So, skip "p == rq->curr" case. Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> Acked-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140128072421.32315.25300.stgit@tkhai Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'linus' into sched/core, to resolve conflictsIngo Molnar2014-02-02
|\| | | | | | | | | | | | | Conflicts: kernel/sysctl.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2014-01-31
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer/dynticks updates from Ingo Molnar: "This tree contains misc dynticks updates: a fix and three cleanups" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/nohz: Fix overflow error in scheduler_tick_max_deferment() nohz_full: fix code style issue of tick_nohz_full_stop_tick nohz: Get timekeeping max deferment outside jiffies_lock tick: Rename tick_check_idle() to tick_irq_enter()
| | * Merge branch 'timers/core' of ↵Ingo Molnar2014-01-25
| | |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/urgent Pull dynticks cleanups from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * sched/nohz: Fix overflow error in scheduler_tick_max_deferment()Kevin Hilman2014-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While calculating the scheduler tick max deferment, the delta is converted from microseconds to nanoseconds through a multiplication against NSEC_PER_USEC. But this microseconds operand is an unsigned int, thus the result may likely overflow. The result is cast to u64 but only once the operation is completed, which is too late to avoid overflown result. This is currently not a problem because the scheduler tick max deferment is 1 second. But this may become an issue as we plan to make this value tunable. So lets fix this by casting the usecs value to u64 before multiplying by NSECS_PER_USEC. Also to prevent from this kind of mistake to happen again, move this ad-hoc jiffies -> nsecs conversion to a new helper. Signed-off-by: Kevin Hilman <khilman@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alex Shi <alex.shi@linaro.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Kevin Hilman <khilman@linaro.org> Link: http://lkml.kernel.org/r/1387315388-31676-2-git-send-email-khilman@linaro.org [move ad-hoc conversion to jiffies_to_nsecs helper] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
| * | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2014-01-31
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A crash fix and documentation updates" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Make sched_class::get_rr_interval() optional sched/deadline: Add sched_dl documentation sched: Fix docbook parameter annotation error in wait.h
| * \ \ \ Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2014-01-25
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A couple of regression fixes mostly hitting virtualized setups, but also some bare metal systems" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/x86/tsc: Initialize multiplier to 0 sched/clock: Fixup early initialization sched/preempt/x86: Fix voluntary preempt for x86 Revert "sched: Fix sleep time double accounting in enqueue entity"
| * | | | | numa: add a sysctl for numa_balancingAndi Kleen2014-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a working sysctl to enable/disable automatic numa memory balancing at runtime. This allows us to track down performance problems with this feature and is generally a good idea. This was possible earlier through debugfs, but only with special debugging options set. Also fix the boot message. [akpm@linux-foundation.org: s/sched_numa_balancing/sysctl_numa_balancing/] Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | Merge branch 'akpm' (incoming from Andrew)Linus Torvalds2014-01-21
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patch-bomb from Andrew Morton: - a couple of misc things - inotify/fsnotify work from Jan - ocfs2 updates (partial) - about half of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) mm/migrate: remove unused function, fail_migrate_page() mm/migrate: remove putback_lru_pages, fix comment on putback_movable_pages mm/migrate: correct failure handling if !hugepage_migration_support() mm/migrate: add comment about permanent failure path mm, page_alloc: warn for non-blockable __GFP_NOFAIL allocation failure mm: compaction: reset scanner positions immediately when they meet mm: compaction: do not mark unmovable pageblocks as skipped in async compaction mm: compaction: detect when scanners meet in isolate_freepages mm: compaction: reset cached scanner pfn's before reading them mm: compaction: encapsulate defer reset logic mm: compaction: trace compaction begin and end memcg, oom: lock mem_cgroup_print_oom_info sched: add tracepoints related to NUMA task migration mm: numa: do not automatically migrate KSM pages mm: numa: trace tasks that fail migration due to rate limiting mm: numa: limit scope of lock for NUMA migrate rate limiting mm: numa: make NUMA-migrate related functions static lib/show_mem.c: show num_poisoned_pages when oom mm/hwpoison: add '#' to hwpoison_inject mm/memblock: use WARN_ONCE when MAX_NUMNODES passed as input parameter ...
| | * | | | | sched: add tracepoints related to NUMA task migrationMel Gorman2014-01-21
| | | |_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds three tracepoints o trace_sched_move_numa when a task is moved to a node o trace_sched_swap_numa when a task is swapped with another task o trace_sched_stick_numa when a numa-related migration fails The tracepoints allow the NUMA scheduler activity to be monitored and the following high-level metrics can be calculated o NUMA migrated stuck nr trace_sched_stick_numa o NUMA migrated idle nr trace_sched_move_numa o NUMA migrated swapped nr trace_sched_swap_numa o NUMA local swapped trace_sched_swap_numa src_nid == dst_nid (should never happen) o NUMA remote swapped trace_sched_swap_numa src_nid != dst_nid (should == NUMA migrated swapped) o NUMA group swapped trace_sched_swap_numa src_ngid == dst_ngid Maybe a small number of these are acceptable but a high number would be a major surprise. It would be even worse if bounces are frequent. o NUMA avg task migs. Average number of migrations for tasks o NUMA stddev task mig Self-explanatory o NUMA max task migs. Maximum number of migrations for a single task In general the intent of the tracepoints is to help diagnose problems where automatic NUMA balancing appears to be doing an excessive amount of useless work. [akpm@linux-foundation.org: remove semicolon-after-if, repair coding-style] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | Merge branch 'for-3.14' of ↵Linus Torvalds2014-01-21
| |\ \ \ \ \ | | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "The bulk of changes are cleanups and preparations for the upcoming kernfs conversion. - cgroup_event mechanism which is and will be used only by memcg is moved to memcg. - pidlist handling is updated so that it can be served by seq_file. Also, the list is not sorted if sane_behavior. cgroup documentation explicitly states that the file is not sorted but it has been for quite some time. - All cgroup file handling now happens on top of seq_file. This is to prepare for kernfs conversion. In addition, all operations are restructured so that they map 1-1 to kernfs operations. - Other cleanups and low-pri fixes" * 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits) cgroup: trivial style updates cgroup: remove stray references to css_id doc: cgroups: Fix typo in doc/cgroups cgroup: fix fail path in cgroup_load_subsys() cgroup: fix missing unlock on error in cgroup_load_subsys() cgroup: remove for_each_root_subsys() cgroup: implement for_each_css() cgroup: factor out cgroup_subsys_state creation into create_css() cgroup: combine css handling loops in cgroup_create() cgroup: reorder operations in cgroup_create() cgroup: make for_each_subsys() useable under cgroup_root_mutex cgroup: css iterations and css_from_dir() are safe under cgroup_mutex cgroup: unify pidlist and other file handling cgroup: replace cftype->read_seq_string() with cftype->seq_show() cgroup: attach cgroup_open_file to all cgroup files cgroup: generalize cgroup_pidlist_open_file cgroup: unify read path so that seq_file is always used cgroup: unify cgroup_write_X64() and cgroup_write_string() cgroup: remove cftype->read(), ->read_map() and ->write() hugetlb_cgroup: convert away from cftype->read() ...
| | * | | | cgroup: replace cftype->read_seq_string() with cftype->seq_show()Tejun Heo2013-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of conversion to kernfs, cgroup file handling is updated so that it can be easily mapped to kernfs. This patch replaces cftype->read_seq_string() with cftype->seq_show() which is not limited to single_open() operation and will map directcly to kernfs seq_file interface. The conversions are mechanical. As ->seq_show() doesn't have @css and @cft, the functions which make use of them are converted to use seq_css() and seq_cft() respectively. In several occassions, e.f. if it has seq_string in its name, the function name is updated to fit the new method better. This patch does not introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Aristeu Rozanski <arozansk@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Neil Horman <nhorman@tuxdriver.com>
| | * | | | cgroup, sched: convert away from cftype->read_map()Tejun Heo2013-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of conversion to kernfs, cgroup file handling is being consolidated so that it can be easily mapped to the seq_file based interface of kernfs. cftype->read_map() doesn't add any value and being replaced with ->read_seq_string(). Update cpu_stats_show() and cpuacct_stats_show() accordingly. This patch doesn't make any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
* | | | | | sched/numa: Turn some magic numbers into #definesRik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup suggested by Mel Gorman. Now the code contains some more hints on what statistics go where. Suggested-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-10-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | sched/numa: Rename variables in task_numa_fault()Rik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We track both the node of the memory after a NUMA fault, and the node of the CPU on which the fault happened. Rename the local variables in task_numa_fault to make things more explicit. Suggested-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-9-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | sched/numa: Do statistics calculation using local variables onlyRik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current code in task_numa_placement calculates the difference between the old and the new value, but also temporarily stores half of the old value in the per-process variables. The NUMA balancing code looks at those per-process variables, and having other tasks temporarily see halved statistics could lead to unwanted numa migrations. This can be avoided by doing all the math in local variables. This change also simplifies the code a little. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-8-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | sched/numa: Normalize faults_cpu stats and weigh by CPU useRik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tracing the code that decides the active nodes has made it abundantly clear that the naive implementation of the faults_from code has issues. Specifically, the garbage collector in some workloads will access orders of magnitudes more memory than the threads that do all the active work. This resulted in the node with the garbage collector being marked the only active node in the group. This issue is avoided if we weigh the statistics by CPU use of each task in the numa group, instead of by how many faults each thread has occurred. To achieve this, we normalize the number of faults to the fraction of faults that occurred on each node, and then multiply that fraction by the fraction of CPU time the task has used since the last time task_numa_placement was invoked. This way the nodes in the active node mask will be the ones where the tasks from the numa group are most actively running, and the influence of eg. the garbage collector and other do-little threads is properly minimized. On a 4 node system, using CPU use statistics calculated over a longer interval results in about 1% fewer page migrations with two 32-warehouse specjbb runs on a 4 node system, and about 5% fewer page migrations, as well as 1% better throughput, with two 8-warehouse specjbb runs, as compared with the shorter term statistics kept by the scheduler. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-7-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | sched/numa, mm: Use active_nodes nodemask to limit numa migrationsRik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the active_nodes nodemask to make smarter decisions on NUMA migrations. In order to maximize performance of workloads that do not fit in one NUMA node, we want to satisfy the following criteria: 1) keep private memory local to each thread 2) avoid excessive NUMA migration of pages 3) distribute shared memory across the active nodes, to maximize memory bandwidth available to the workload This patch accomplishes that by implementing the following policy for NUMA migrations: 1) always migrate on a private fault 2) never migrate to a node that is not in the set of active nodes for the numa_group 3) always migrate from a node outside of the set of active nodes, to a node that is in that set 4) within the set of active nodes in the numa_group, only migrate from a node with more NUMA page faults, to a node with fewer NUMA page faults, with a 25% margin to avoid ping-ponging This results in most pages of a workload ending up on the actively used nodes, with reduced ping-ponging of pages between those nodes. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-6-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | sched/numa: Build per numa_group active node mask from numa_faults_cpu ↵Rik van Riel2014-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | statistics The numa_faults_cpu statistics are used to maintain an active_nodes nodemask per numa_group. This allows us to be smarter about when to do numa migrations. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Link: http://lkml.kernel.org/r/1390860228-21539-5-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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