Re: Boot time regression in 2.6.38 after initial wq merge

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Feb 22, 2011 at 08:32:55PM +0100, pantherchen@versanet.de wrote:
> On 02/22/2011 06:59 PM, Dmitry Torokhov wrote:
> >On Tue, Feb 22, 2011 at 09:22:54AM -0800, Dmitry Torokhov wrote:
> >>Just to confirm, if you revert commit
> >>
> >>	8ee294cd9def0004887da7f44b80563493b0a097
> >>
> >>from 2.6.38-rc6, does this restore boot time?
> 
> Yes, it's booting fine with that commit reverted.
> 
> >And if that indeed fixes the issue I wonder if the reason for the stall
> >is that we trip on flush_scheduled_work() somewhere. If you could stick
> >dump_stack() into flush_scheduled_work() that might give us some clues.
> 
> I wasn't sure where to put the dump_stack() call, so I placed one
> before and one after the flush_workqueue() call.
> 
> Here's the part that turned up in dmesg: http://paste.ubuntu.com/570729/
> 

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);

?

Thanks.

-- 
Dmitry