2009-09-16 08:54:45 +02:00
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/*
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* Only give sleepers 50% of their service deficit. This allows
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* them to run sooner, but does not allow tons of sleepers to
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* rip the spread apart.
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*/
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SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
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2009-09-11 12:31:23 +02:00
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/*
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* Place new tasks ahead so that they do not starve already running
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* tasks
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*/
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2008-04-19 19:45:00 +02:00
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SCHED_FEAT(START_DEBIT, 1)
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2009-09-11 12:31:23 +02:00
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/*
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* Based on load and program behaviour, see if it makes sense to place
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* a newly woken task on the same cpu as the task that woke it --
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* improve cache locality. Typically used with SYNC wakeups as
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* generated by pipes and the like, see also SYNC_WAKEUPS.
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*/
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2008-04-19 19:45:00 +02:00
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SCHED_FEAT(AFFINE_WAKEUPS, 1)
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2009-09-11 12:31:23 +02:00
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/*
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* Prefer to schedule the task we woke last (assuming it failed
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* wakeup-preemption), since its likely going to consume data we
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* touched, increases cache locality.
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*/
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sched: Improve latencies and throughput
Make the idle balancer more agressive, to improve a
x264 encoding workload provided by Jason Garrett-Glaser:
NEXT_BUDDY NO_LB_BIAS
encoded 600 frames, 252.82 fps, 22096.60 kb/s
encoded 600 frames, 250.69 fps, 22096.60 kb/s
encoded 600 frames, 245.76 fps, 22096.60 kb/s
NO_NEXT_BUDDY LB_BIAS
encoded 600 frames, 344.44 fps, 22096.60 kb/s
encoded 600 frames, 346.66 fps, 22096.60 kb/s
encoded 600 frames, 352.59 fps, 22096.60 kb/s
NO_NEXT_BUDDY NO_LB_BIAS
encoded 600 frames, 425.75 fps, 22096.60 kb/s
encoded 600 frames, 425.45 fps, 22096.60 kb/s
encoded 600 frames, 422.49 fps, 22096.60 kb/s
Peter pointed out that this is better done via newidle_idx,
not via LB_BIAS, newidle balancing should look for where
there is load _now_, not where there was load 2 ticks ago.
Worst-case latencies are improved as well as no buddies
means less vruntime spread. (as per prior lkml discussions)
This change improves kbuild-peak parallelism as well.
Reported-by: Jason Garrett-Glaser <darkshikari@gmail.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1253011667.9128.16.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 15:07:03 +02:00
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SCHED_FEAT(NEXT_BUDDY, 0)
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2009-09-11 12:31:23 +02:00
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/*
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* Prefer to schedule the task that ran last (when we did
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* wake-preempt) as that likely will touch the same data, increases
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* cache locality.
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*/
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SCHED_FEAT(LAST_BUDDY, 1)
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/*
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* Consider buddies to be cache hot, decreases the likelyness of a
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* cache buddy being migrated away, increases cache locality.
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*/
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2008-04-19 19:45:00 +02:00
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SCHED_FEAT(CACHE_HOT_BUDDY, 1)
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2009-09-11 12:31:23 +02:00
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2009-09-03 13:20:03 +02:00
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/*
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* Use arch dependent cpu power functions
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*/
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SCHED_FEAT(ARCH_POWER, 0)
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2008-10-20 14:27:43 +02:00
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SCHED_FEAT(HRTICK, 0)
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2008-04-19 19:45:00 +02:00
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SCHED_FEAT(DOUBLE_TICK, 0)
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2008-08-20 12:44:55 +02:00
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SCHED_FEAT(LB_BIAS, 1)
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2009-09-11 12:31:23 +02:00
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/*
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* Spin-wait on mutex acquisition when the mutex owner is running on
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* another cpu -- assumes that when the owner is running, it will soon
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* release the lock. Decreases scheduling overhead.
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*/
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2009-01-12 14:01:47 +01:00
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SCHED_FEAT(OWNER_SPIN, 1)
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2010-10-05 02:03:22 +02:00
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/*
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2011-07-11 21:28:18 +02:00
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* Decrement CPU power based on time not spent running tasks
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2010-10-05 02:03:22 +02:00
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*/
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2011-07-11 21:28:18 +02:00
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SCHED_FEAT(NONTASK_POWER, 1)
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2011-04-05 17:23:58 +02:00
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/*
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* Queue remote wakeups on the target CPU and process them
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* using the scheduler IPI. Reduces rq->lock contention/bounces.
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*/
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SCHED_FEAT(TTWU_QUEUE, 1)
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2011-07-15 10:35:52 +02:00
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SCHED_FEAT(FORCE_SD_OVERLAP, 0)
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2011-10-06 22:39:14 +02:00
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SCHED_FEAT(RT_RUNTIME_SHARE, 1)
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