Groups > linux.kernel > #1190037

Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs

From	Mike Galbraith <umgwanakikbuti@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs
Date	2015-07-22 17:00 +0200
Message-ID	<pP3EZ-1wt-13@gated-at.bofh.it> (permalink)
References	(5 earlier) <pNAvn-5wn-3@gated-at.bofh.it> <pNRPz-5dL-3@gated-at.bofh.it> <pOBz4-3p0-5@gated-at.bofh.it> <pOULo-5OL-9@gated-at.bofh.it> <pP32i-Ny-31@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, 2015-07-22 at 10:11 -0400, Tejun Heo wrote:
> On Wed, Jul 22, 2015 at 07:24:46AM +0200, Mike Galbraith wrote:
> > WORK_CPU_UNBOUND work items queued to a bound workqueue always run
> > locally.  This is a good thing normally, but not when the user has
> 
> The constant name used there is a bit misleading but you can't put
> work items which are queued w/ queue_work() on foreign cpus by
> default.  queue_work() has always guaranteed local execution.  The
> problem is that workqueue can't currently tell whether a queue_work()
> user expects cpu locality for correctness or optimization.  It'd be
> great if we introduce queue_work_on_local() or sth and replace
> correctness ones with it but that involves auditing each and every
> queue_work() usage.  If anybody is up for the task, I'd be happy to
> help.

Oh well.  That puts a big dent in the utility of wq_unbound_cpumask, but
too bad.  If someone has a big enough HPC itch, they'll scratch it.

	-Mike

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

[RFC] workqueue: avoiding unbounded wq on isolated CPUs by default Daniel Bristot de Oliveira <bristot@redhat.com> - 2015-07-16 21:20 +0200
  Re: [RFC] workqueue: avoiding unbounded wq on isolated CPUs by  default Tejun Heo <tj@kernel.org> - 2015-07-16 21:30 +0200
    Re: [RFC] workqueue: avoiding unbounded wq on isolated CPUs by  default Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-17 06:30 +0200
      Re: [RFC] workqueue: avoiding unbounded wq on isolated CPUs by  default Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-19 10:10 +0200
        Re: [RFC] workqueue: avoiding unbounded wq on isolated CPUs by  default Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-19 14:20 +0200
        [patch] workqueue: schedule WORK_CPU_UNBOUND work on  wq_unbound_cpumask CPUs Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-22 07:30 +0200
          [PATCH] workqueue: avoiding unbounded wq on isolated CPUs by default Daniel Bristot de Oliveira <bristot@redhat.com> - 2015-07-22 14:50 +0200
          Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on  wq_unbound_cpumask CPUs Tejun Heo <tj@kernel.org> - 2015-07-22 16:20 +0200
            Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on  wq_unbound_cpumask CPUs Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-22 17:00 +0200
              Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on  wq_unbound_cpumask CPUs Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-07-22 17:20 +0200
                Re: [patch] workqueue: schedule WORK_CPU_UNBOUND work on  wq_unbound_cpumask CPUs Tejun Heo <tj@kernel.org> - 2015-07-22 17:30 +0200

csiph-web