diff options
| author | John Stultz <jstultz@google.com> | 2026-03-24 19:13:17 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-04-03 14:23:38 +0200 |
| commit | 37341ec573da7c16fdd45222b1bfb7b421dbdbcb (patch) | |
| tree | 18eed18325c60cc2ce482c19eaf1c4fcef18f199 /kernel | |
| parent | e0ca8991b2de6c9dfe6fcd8a0364951b2bd56797 (diff) | |
sched: Minimise repeated sched_proxy_exec() checking
Peter noted: Compilers are really bad (as in they utterly refuse)
optimizing (even when marked with __pure) the static branch
things, and will happily emit multiple identical in a row.
So pull out the one obvious sched_proxy_exec() branch in
__schedule() and remove some of the 'implicit' ones in that
path.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260324191337.1841376-3-jstultz@google.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 29741685762d..f3306d3f2aa1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6597,11 +6597,7 @@ find_proxy_task(struct rq *rq, struct task_struct *donor, struct rq_flags *rf) struct mutex *mutex; /* Follow blocked_on chain. */ - for (p = donor; task_is_blocked(p); p = owner) { - mutex = p->blocked_on; - /* Something changed in the chain, so pick again */ - if (!mutex) - return NULL; + for (p = donor; (mutex = p->blocked_on); p = owner) { /* * By taking mutex->wait_lock we hold off concurrent mutex_unlock() * and ensure @owner sticks around. @@ -6832,12 +6828,14 @@ pick_again: next = pick_next_task(rq, rq->donor, &rf); rq_set_donor(rq, next); rq->next_class = next->sched_class; - if (unlikely(task_is_blocked(next))) { - next = find_proxy_task(rq, next, &rf); - if (!next) - goto pick_again; - if (next == rq->idle) - goto keep_resched; + if (sched_proxy_exec()) { + if (unlikely(next->blocked_on)) { + next = find_proxy_task(rq, next, &rf); + if (!next) + goto pick_again; + if (next == rq->idle) + goto keep_resched; + } } picked: clear_tsk_need_resched(prev); |