Re: konqueror deadlocks on 2.6.22

From: Al Boldi
Date: Tue Jan 22 2008 - 08:24:47 EST


Ingo Molnar wrote:
> * Oliver Pinter (Pintér Olivér) <oliver.pntr@xxxxxxxxx> wrote:
> > and then please update to CFS-v24.1
> > http://people.redhat.com/~mingo/cfs-scheduler/sched-cfs-v2.6.22.15-v24.1
> >.patch
> >
> > > Yes with CFSv20.4, as in the log.
> > >
> > > It also hangs on 2.6.23.13
>
> my feeling is that this is some sort of timing dependent race in
> konqueror/kde/qt that is exposed when a different scheduler is put in.
>
> If it disappears with CFS-v24.1 it is probably just because the timings
> will change again. Would be nice to debug this on the konqueror side and
> analyze why it fails and how. You can probably tune the timings by
> enabling SCHED_DEBUG and tweaking /proc/sys/kernel/*sched* values - in
> particular sched_latency and the granularity settings. Setting wakeup
> granularity to 0 might be one of the things that could make a
> difference.

Thanks Ingo, but Mike suggested that data=writeback may make a difference,
which it does indeed.

So the bug seems to be related to data=ordered, although I haven't gotten any
feedback from the ext3 gurus yet.

Seems rather critical though, as data=writeback is a dangerous mode to run.


Thanks!

--
Al

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