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| author | Peter Zijlstra <peterz@infradead.org> | 2009-09-16 12:31:31 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-17 10:17:25 +0200 |
| commit | ad4b78bbcbab66998b05d422ac6106b645796e54 (patch) | |
| tree | 45f3561f4bd6b886948a3b0eea64edab9bab9eda /kernel/sched_features.h | |
| parent | eb24073bc1fe3e569a855cf38d529fb650c35524 (diff) | |
| download | lwn-ad4b78bbcbab66998b05d422ac6106b645796e54.tar.gz lwn-ad4b78bbcbab66998b05d422ac6106b645796e54.zip | |
sched: Add new wakeup preemption mode: WAKEUP_RUNNING
Create a new wakeup preemption mode, preempt towards tasks that run
shorter on avg. It sets next buddy to be sure we actually run the task
we preempted for.
Test results:
root@twins:~# while :; do :; done &
[1] 6537
root@twins:~# while :; do :; done &
[2] 6538
root@twins:~# while :; do :; done &
[3] 6539
root@twins:~# while :; do :; done &
[4] 6540
root@twins:/home/peter# ./latt -c4 sleep 4
Entries: 48 (clients=4)
Averages:
------------------------------
Max 4750 usec
Avg 497 usec
Stdev 737 usec
root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features
root@twins:/home/peter# ./latt -c4 sleep 4
Entries: 48 (clients=4)
Averages:
------------------------------
Max 14 usec
Avg 5 usec
Stdev 3 usec
Disabled by default - needs more testing.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>
Diffstat (limited to 'kernel/sched_features.h')
| -rw-r--r-- | kernel/sched_features.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/sched_features.h b/kernel/sched_features.h index d5059fd761d9..0d94083582c7 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -54,6 +54,11 @@ SCHED_FEAT(WAKEUP_SYNC, 0) SCHED_FEAT(WAKEUP_OVERLAP, 0) /* + * Wakeup preemption towards tasks that run short + */ +SCHED_FEAT(WAKEUP_RUNNING, 0) + +/* * Use the SYNC wakeup hint, pipes and the likes use this to indicate * the remote end is likely to consume the data we just wrote, and * therefore has cache benefit from being placed on the same cpu, see |