Le Fri, Sep 19, 2025 at 04:50:37PM +0200, Marco Crivellari a écrit : > Currently if a user enqueue a work item using schedule_delayed_work() the > used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use > WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to > schedule_work() that is using system_wq and queue_work(), that makes use > again of WORK_CPU_UNBOUND. > > This lack of consistentcy cannot be addressed without refactoring the API. > > system_wq is a per-CPU worqueue, yet nothing in its name tells about that > CPU affinity constraint, which is very often not required by users. Make > it clear by adding a system_percpu_wq. > > The old wq will be kept for a few release cylces. > > Suggested-by: Tejun Heo <[email protected]> > Signed-off-by: Marco Crivellari <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]> > --- > kernel/rcu/tasks.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > index f92443561d36..2dc044fd126e 100644 > --- a/kernel/rcu/tasks.h > +++ b/kernel/rcu/tasks.h > @@ -553,13 +553,13 @@ static void rcu_tasks_invoke_cbs(struct rcu_tasks *rtp, > struct rcu_tasks_percpu > rtpcp_next = rtp->rtpcp_array[index]; > if (rtpcp_next->cpu < > smp_load_acquire(&rtp->percpu_dequeue_lim)) { > cpuwq = rcu_cpu_beenfullyonline(rtpcp_next->cpu) ? > rtpcp_next->cpu : WORK_CPU_UNBOUND; > - queue_work_on(cpuwq, system_wq, &rtpcp_next->rtp_work); > + queue_work_on(cpuwq, system_percpu_wq, > &rtpcp_next->rtp_work); > index++; > if (index < num_possible_cpus()) { > rtpcp_next = rtp->rtpcp_array[index]; > if (rtpcp_next->cpu < > smp_load_acquire(&rtp->percpu_dequeue_lim)) { > cpuwq = > rcu_cpu_beenfullyonline(rtpcp_next->cpu) ? rtpcp_next->cpu : WORK_CPU_UNBOUND; > - queue_work_on(cpuwq, system_wq, > &rtpcp_next->rtp_work); > + queue_work_on(cpuwq, system_percpu_wq, > &rtpcp_next->rtp_work); > } > } > } > -- > 2.51.0 > -- Frederic Weisbecker SUSE Labs
