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| author | Dave Kleikamp <dave.kleikamp@oracle.com> | 2017-05-15 14:14:13 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-23 10:01:34 +0200 |
| commit | c249f255aab86b9b187ba319b9d2684841ac7c8d (patch) | |
| tree | 995fbe15e1c550ea496acebb8fc1c874b24f989c /init | |
| parent | 896bbb2522587e3b8eb2a0d204d43ccc1042a00d (diff) | |
| download | linux-stable-c249f255aab86b9b187ba319b9d2684841ac7c8d.tar.gz linux-stable-c249f255aab86b9b187ba319b9d2684841ac7c8d.tar.bz2 linux-stable-c249f255aab86b9b187ba319b9d2684841ac7c8d.zip | |
sched/rt: Minimize rq->lock contention in do_sched_rt_period_timer()
With CONFIG_RT_GROUP_SCHED=y, do_sched_rt_period_timer() sequentially
takes each CPU's rq->lock. On a large, busy system, the cumulative time it
takes to acquire each lock can be excessive, even triggering a watchdog
timeout.
If rt_rq->rt_time and rt_rq->rt_nr_running are both zero, this function does
nothing while holding the lock, so don't bother taking it at all.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a767637b-df85-912f-ba69-c90ee00a3fb6@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions