diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2022-08-22 19:39:56 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-18 13:55:09 -0800 |
| commit | 8baceabca656d5ef4494cdeb3b9b9fbb844ac613 (patch) | |
| tree | b60ac4475d4ad3d2b3ddf83a6d0adb199ca48a2e /kernel/sched | |
| parent | 333d073dee3a6865171d43e3b0a9ff688bff5891 (diff) | |
sched/fair: use try_cmpxchg in task_numa_work
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
task_numa_work. x86 CMPXCHG instruction returns success in ZF flag, so
this change saves a compare after cmpxchg (and related move instruction in
front of cmpxchg).
No functional change intended.
Link: https://lkml.kernel.org/r/20220822173956.82525-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index e4a0b8bd941c..d6fa06f036e1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2964,7 +2964,7 @@ static void task_numa_work(struct callback_head *work) } next_scan = now + msecs_to_jiffies(p->numa_scan_period); - if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate) + if (!try_cmpxchg(&mm->numa_next_scan, &migrate, next_scan)) return; /* |