* Re: [RFC 1/4] workqueue: fix selecting cpu for queuing work [not found] ` <20191211105919.10652-1-hdanton@sina.com> @ 2019-12-11 23:07 ` Daniel Jordan 2020-01-23 22:37 ` Daniel Jordan 0 siblings, 1 reply; 3+ messages in thread From: Daniel Jordan @ 2019-12-11 23:07 UTC (permalink / raw) To: Hillf Danton; +Cc: linux-kernel, linux-mm, Tejun Heo, Lai Jiangshan [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> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC 1/4] workqueue: fix selecting cpu for queuing work 2019-12-11 23:07 ` [RFC 1/4] workqueue: fix selecting cpu for queuing work Daniel Jordan @ 2020-01-23 22:37 ` Daniel Jordan 0 siblings, 0 replies; 3+ messages in thread From: Daniel Jordan @ 2020-01-23 22:37 UTC (permalink / raw) To: Hillf Danton; +Cc: linux-kernel, linux-mm, Tejun Heo, Lai Jiangshan 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 > > > > ^ permalink raw reply [flat|nested] 3+ messages in thread
[parent not found: <20191211112229.22652-1-hdanton@sina.com>]
* Re: [RFC 3/4] workqueue: reap dead pool workqueue on queuing work [not found] ` <20191211112229.22652-1-hdanton@sina.com> @ 2019-12-11 23:25 ` Daniel Jordan 0 siblings, 0 replies; 3+ messages in thread From: Daniel Jordan @ 2019-12-11 23:25 UTC (permalink / raw) To: Hillf Danton; +Cc: linux-kernel, linux-mm, Tejun Heo, Lai Jiangshan On Wed, Dec 11, 2019 at 07:22:29PM +0800, Hillf Danton wrote: > Release rcu lock to reap dead pool workqueue. What's to be gained by reaping the pwq (and possibly worker pool and wq) before __queue_work() retries? It'll just happen after the queueing finishes. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-01-23 22:37 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <20191211104601.16468-1-hdanton@sina.com> [not found] ` <20191211105919.10652-1-hdanton@sina.com> 2019-12-11 23:07 ` [RFC 1/4] workqueue: fix selecting cpu for queuing work Daniel Jordan 2020-01-23 22:37 ` Daniel Jordan [not found] ` <20191211112229.22652-1-hdanton@sina.com> 2019-12-11 23:25 ` [RFC 3/4] workqueue: reap dead pool workqueue on " Daniel Jordan
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