Messages in this thread | | | Date | Wed, 23 Feb 2011 10:38:54 +0100 | From | Tejun Heo <> | Subject | Re: Boot time regression in 2.6.38 after initial wq merge |
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Hello,
On Tue, Feb 22, 2011 at 09:20:42PM -0800, Dmitry Torokhov wrote: > On Tue, Feb 22, 2011 at 09:14:46PM +0100, pantherchen@versanet.de wrote: > > On 02/22/2011 08:52 PM, Dmitry Torokhov wrote: > > >Ewww... tty/ldisc... > > > > > >Does it help if you change drivers/input/serio/serio.c::serio_queue_event() > > >from calling > > > > > > schedule_work(&serio_event_work); > > > > > >to call > > > > > > queue_work(system_long_wq,&serio_event_work); > > > > > >? > > > > Yes, that works: http://img.xrmb2.net/images/499337.png > > > > Great! > > OK, so below is properly formatted patch. I am going to send it upstream > unless somebody objects.
Ah, okay, thanks a lot for tracking this down, Dmitry. Didn't expect flush_scheduled_work() to bite back this way. :-)
> Input: serio/gameport - use 'long' system workqueue > > From: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > Commit 8ee294cd9def0004887da7f44b80563493b0a097 converted serio > subsystem event handling from using a dedicated thread to using > common workqueue. Unfortunately, this regressed our boot times, > due to the fact that serio jobs take long time to execute. While > the new concurrency managed workqueue code manages long-playing > works just fine and schedules additional workers as needed, such > works wreck havoc among remaining users of flush_scheduled_work(). > > To solve this problem let's move serio/gameport works from system_wq > to system_long_wq which nobody tries to flush. > > Reported-and-tested-by: Hernando Torque <pantherchen@versanet.de> > Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Tejun Heo <tj@kernel.org>
Most flush_scheduled_work() users are already gone and once all of them are gone, system_long_wq can be removed without causing any difference.
Thank you.
-- tejun
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