[tip: sched/urgent] sched/core: Call wq_worker_tick() for the execution context

[tip-bot2 for Hui Su]

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID:     f5741d2b34519d387edf6e9798fc7030c20a35f3
Gitweb:        https://git.kernel.org/tip/f5741d2b34519d387edf6e9798fc7030c20a35f3
Author:        Hui Su <sh_def@xxxxxxx>
AuthorDate:    Wed, 02 Sep 2026 23:02:09 +08:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 10 Sep 2026 10:22:52 +02:00

sched/core: Call wq_worker_tick() for the execution context

wq_worker_tick() accounts CPU time and detects CPU-intensive work for
the kworker that is actually running. With proxy execution, rq->donor
is the scheduling context while rq->curr is the execution context.

Calling the hook with rq->donor can skip workqueue accounting when a
kworker is executing on behalf of a donor task. It can also account a
blocked kworker when the donor is a worker but rq->curr is the task
actually executing. The former can delay WORKER_CPU_INTENSIVE handling
and pool concurrency management, which can delay pending kernel work
and userspace operations depending on it.

Use rq->curr for the workqueue tick hook while retaining rq->donor for
scheduler accounting.

Fixes: af0c8b2bf67b ("sched: Split scheduler and execution contexts")
Signed-off-by: Hui Su <sh_def@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Link: https://patch.msgid.link/20260902150208.1209922-2-sh_def@xxxxxxx
---
 kernel/sched/core.c |  9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b998ef6..7885ff7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5776,8 +5776,8 @@ void sched_tick(void)
 {
 	int cpu = smp_processor_id();
 	struct rq *rq = cpu_rq(cpu);
-	/* accounting goes to the donor task */
-	struct task_struct *donor;
+	/* scheduler accounting goes to the donor task */
+	struct task_struct *curr, *donor;
 	struct rq_flags rf;
 	unsigned long hw_pressure;
 	u64 resched_latency;
@@ -5788,6 +5788,7 @@ void sched_tick(void)
 	sched_clock_tick();
 
 	rq_lock(rq, &rf);
+	curr = rq->curr;
 	donor = rq->donor;
 
 	psi_account_irqtime(rq, donor, NULL);
@@ -5813,8 +5814,8 @@ void sched_tick(void)
 
 	perf_event_task_tick();
 
-	if (donor->flags & PF_WQ_WORKER)
-		wq_worker_tick(donor);
+	if (curr->flags & PF_WQ_WORKER)
+		wq_worker_tick(curr);
 
 	if (!scx_switched_all()) {
 		rq->idle_balance = idle_cpu(cpu);