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@163.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://patch.msgid.link/20260902150208.1209922-2-sh_def@163.com

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b998ef6b87af4fa60422fe86b3702c43103ea9aa..7885ff76e69f28e1c81d72d87e5ceef0562ccea9 100644 (file)
--- 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);