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| author | Peter Zijlstra <peterz@infradead.org> | 2025-10-30 12:56:34 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-12-14 08:25:02 +0100 |
| commit | 47efe2ddccb1f285a02bfcf1e079f49bf7a9ccb3 (patch) | |
| tree | 557b60f21d268d3f797964b4c7f0f98f9fd19908 | |
| parent | 95a0155224a658965f34ed4b1943b238d9be1fea (diff) | |
| download | tip-47efe2ddccb1f285a02bfcf1e079f49bf7a9ccb3.tar.gz | |
sched/core: Add assertions to QUEUE_CLASS
Add some checks to the sched_change pattern to validate assumptions
around changing classes.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20251127154725.771691954@infradead.org
| -rw-r--r-- | kernel/sched/core.c | 13 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 1 |
2 files changed, 14 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 41ba0be1691174..4479f7d1fdfb60 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10782,6 +10782,7 @@ struct sched_change_ctx *sched_change_begin(struct task_struct *p, unsigned int *ctx = (struct sched_change_ctx){ .p = p, + .class = p->sched_class, .flags = flags, .queued = task_on_rq_queued(p), .running = task_current_donor(rq, p), @@ -10812,6 +10813,11 @@ void sched_change_end(struct sched_change_ctx *ctx) lockdep_assert_rq_held(rq); + /* + * Changing class without *QUEUE_CLASS is bad. + */ + WARN_ON_ONCE(p->sched_class != ctx->class && !(ctx->flags & ENQUEUE_CLASS)); + if ((ctx->flags & ENQUEUE_CLASS) && p->sched_class->switching_to) p->sched_class->switching_to(rq, p); @@ -10823,6 +10829,13 @@ void sched_change_end(struct sched_change_ctx *ctx) if (ctx->flags & ENQUEUE_CLASS) { if (p->sched_class->switched_to) p->sched_class->switched_to(rq, p); + + /* + * If this was a degradation in class someone should have set + * need_resched by now. + */ + WARN_ON_ONCE(sched_class_above(ctx->class, p->sched_class) && + !test_tsk_need_resched(p)); } else { p->sched_class->prio_changed(rq, p, ctx->prio); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 67cff7d6cc2ff1..a40582d5b28820 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3968,6 +3968,7 @@ extern void balance_callbacks(struct rq *rq, struct balance_callback *head); struct sched_change_ctx { u64 prio; struct task_struct *p; + const struct sched_class *class; int flags; bool queued; bool running; |