diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-07-12 03:33:49 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-07-14 17:16:33 +0200 |
| commit | 7de9d4f946383f48ec393b6e9ad0c20e49e174e7 (patch) | |
| tree | 7d5af61cdcb15dddf2663782c175ce7d402103ad /kernel/sched/fair.c | |
| parent | be39617e38e0b1939a6014d77ee6f14707d59b1b (diff) | |
sched: Start blocked_on chain processing in find_proxy_task()
Start to flesh out the real find_proxy_task() implementation,
but avoid the migration cases for now, in those cases just
deactivate the donor task and pick again.
To ensure the donor task or other blocked tasks in the chain
aren't migrated away while we're running the proxy, also tweak
the fair class logic to avoid migrating donor or mutex blocked
tasks.
[jstultz: This change was split out from the larger proxy patch]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Connor O'Brien <connoro@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lkml.kernel.org/r/20250712033407.2383110-9-jstultz@google.com
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 97176458f2be..b173a059315c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9291,7 +9291,8 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) * 2) throttled_lb_pair, or * 3) cannot be migrated to this CPU due to cpus_ptr, or * 4) running (obviously), or - * 5) are cache-hot on their current CPU. + * 5) are cache-hot on their current CPU, or + * 6) are blocked on mutexes (if SCHED_PROXY_EXEC is enabled) */ if ((p->se.sched_delayed) && (env->migration_type != migrate_load)) return 0; @@ -9313,6 +9314,9 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) if (kthread_is_per_cpu(p)) return 0; + if (task_is_blocked(p)) + return 0; + if (!cpumask_test_cpu(env->dst_cpu, p->cpus_ptr)) { int cpu; @@ -9348,7 +9352,8 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) /* Record that we found at least one task that could run on dst_cpu */ env->flags &= ~LBF_ALL_PINNED; - if (task_on_cpu(env->src_rq, p)) { + if (task_on_cpu(env->src_rq, p) || + task_current_donor(env->src_rq, p)) { schedstat_inc(p->stats.nr_failed_migrations_running); return 0; } @@ -9392,6 +9397,9 @@ static void detach_task(struct task_struct *p, struct lb_env *env) schedstat_inc(p->stats.nr_forced_migrations); } + WARN_ON(task_current(env->src_rq, p)); + WARN_ON(task_current_donor(env->src_rq, p)); + deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK); set_task_cpu(p, env->dst_cpu); } |