Messages in this thread | | | Date | Wed, 3 Nov 2010 06:51:07 +1000 | Subject | Re: lockdep and oops_in_progress | From | Dave Airlie <> |
| |
On Fri, Aug 6, 2010 at 12:59 AM, Yong Zhang <yong.zhang0@gmail.com> wrote: > On Thu, Aug 05, 2010 at 10:10:49AM +0200, Peter Zijlstra wrote: >> On Thu, 2010-08-05 at 16:21 +1000, Dave Airlie wrote: >> > Hi guys, >> > >> > I was debugging a wierd issue with suspend/resume and fbcon/X with >> > some recent work Jesse and myself did to try and make sure a pinned >> > fbcon always gets the text on it with a panic or oops occurs. >> > >> > It does this by testing the oops_in_progress flag, however once any >> > lockdep issue occurs it looks to me that we leave this flag set >> > forever, in most places I can see in oops code etc they call >> > bust_spinlocks(1) then bust_spinlocks(0) to balance the >> > oops_in_progress value, but lockdep never seems to reset it. >> > >> > I'm wondering if there is an inherent reason for this or if I whip up >> > a patch to reset once the lockdep is printed if this would cause any >> > issues? >> >> That's debug_locks_off(), right? I don't think there's a particular >> reason we keep it set, cleaning that up might take a bit of work but >> shouldn't be too hard. > > commit e0fdace10e75dac67d906213b780ff1b1a4cc360 > Author: David Miller <davem@davemloft.net> > Date: Fri Aug 1 01:11:22 2008 -0700 > > debug_locks: set oops_in_progress if we will log messages. > > Otherwise lock debugging messages on runqueue locks can deadlock the > system due to the wakeups performed by printk(). > > Signed-off-by: David S. Miller <davem@davemloft.net> > Signed-off-by: Ingo Molnar <mingo@elte.hu> > > Seems we can revert that commit now because of 'robustify printk'. > > Dave, what do you think about it?
Hey DaveM, as mentioned at KS,
Dave. -- 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/
| |