| Message ID | 20191211105919.10652-1-hdanton@sina.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | workqueue: fix selecting cpu for queuing work and cleanup | expand |
[please cc maintainers] On Wed, Dec 11, 2019 at 06:59:19PM +0800, Hillf Danton wrote: > Round robin is needed only for unbound workqueue and wq_unbound_cpumask > has nothing to do with standard workqueues, so we have to select cpu in > case of WORK_CPU_UNBOUND also with workqueue type taken into account. Good catch. I'd include something like this in the changelog. Otherwise, work queued on a bound workqueue with WORK_CPU_UNBOUND might not prefer the local CPU if wq_unbound_cpumask is non-empty and doesn't include that CPU. With that you can add Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
On Wed, Dec 11, 2019 at 06:07:35PM -0500, Daniel Jordan wrote: > [please cc maintainers] > > On Wed, Dec 11, 2019 at 06:59:19PM +0800, Hillf Danton wrote: > > Round robin is needed only for unbound workqueue and wq_unbound_cpumask > > has nothing to do with standard workqueues, so we have to select cpu in > > case of WORK_CPU_UNBOUND also with workqueue type taken into account. > > Good catch. I'd include something like this in the changelog. > > Otherwise, work queued on a bound workqueue with WORK_CPU_UNBOUND might > not prefer the local CPU if wq_unbound_cpumask is non-empty and doesn't > include that CPU. > > With that you can add > > Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Any plans to repost this patch, Hillf? If not, I can do it while retaining your authorship. Adding back the context, which I forgot to keep when adding the maintainers. > > Fixes: ef557180447f ("workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs") > > Signed-off-by: Hillf Danton <hdanton@sina.com> > > --- > > > > --- a/kernel/workqueue.c > > +++ c/kernel/workqueue.c > > @@ -1409,16 +1409,19 @@ static void __queue_work(int cpu, struct > > if (unlikely(wq->flags & __WQ_DRAINING) && > > WARN_ON_ONCE(!is_chained_work(wq))) > > return; > > + > > rcu_read_lock(); > > retry: > > - if (req_cpu == WORK_CPU_UNBOUND) > > - cpu = wq_select_unbound_cpu(raw_smp_processor_id()); > > - > > /* pwq which will be used unless @work is executing elsewhere */ > > - if (!(wq->flags & WQ_UNBOUND)) > > - pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); > > - else > > + if (wq->flags & WQ_UNBOUND) { > > + if (req_cpu == WORK_CPU_UNBOUND) > > + cpu = wq_select_unbound_cpu(raw_smp_processor_id()); > > pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); > > + } else { > > + if (req_cpu == WORK_CPU_UNBOUND) > > + cpu = raw_smp_processor_id(); > > + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); > > + } > > > > /* > > * If @work was previously on a different pool, it might still be > > > >
On Thu, 23 Jan 2020 17:37:43 -0500 Daniel Jordan wrote: > > Any plans to repost this patch, Hillf? If not, I can do it while retaining > your authorship. Feel free to do it please and a Cc is enough. Thanks Hillf
--- a/kernel/workqueue.c +++ c/kernel/workqueue.c @@ -1409,16 +1409,19 @@ static void __queue_work(int cpu, struct if (unlikely(wq->flags & __WQ_DRAINING) && WARN_ON_ONCE(!is_chained_work(wq))) return; + rcu_read_lock(); retry: - if (req_cpu == WORK_CPU_UNBOUND) - cpu = wq_select_unbound_cpu(raw_smp_processor_id()); - /* pwq which will be used unless @work is executing elsewhere */ - if (!(wq->flags & WQ_UNBOUND)) - pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); - else + if (wq->flags & WQ_UNBOUND) { + if (req_cpu == WORK_CPU_UNBOUND) + cpu = wq_select_unbound_cpu(raw_smp_processor_id()); pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); + } else { + if (req_cpu == WORK_CPU_UNBOUND) + cpu = raw_smp_processor_id(); + pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); + } /* * If @work was previously on a different pool, it might still be
Round robin is needed only for unbound workqueue and wq_unbound_cpumask has nothing to do with standard workqueues, so we have to select cpu in case of WORK_CPU_UNBOUND also with workqueue type taken into account. Fixes: ef557180447f ("workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs") Signed-off-by: Hillf Danton <hdanton@sina.com> ---