On Sat, May 11, 2013 at 12:48:49AM -0400, Michael L. Semon wrote:
> On 05/10/2013 09:17 PM, Dave Chinner wrote:
> >On Fri, May 10, 2013 at 03:07:19PM -0400, Michael L. Semon wrote:
> >>On Thu, May 9, 2013 at 10:19 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> >>>On Thu, May 09, 2013 at 10:00:10PM -0400, Michael L. Semon wrote:
>
> >>Thanks for looking at it. There are going to be plenty of false
> >>positives out there. Is there a pecking order of what works best? As
> >>in...
> >>
> >>* IRQ (IRQs-off?) checking: worth reporting...?
> >>* sleep inside atomic sections: fascinating, but almost anything can
> >>trigger it
> >>* multiple-CPU deadlock detection: can only speculate on a uniprocessor
> >>system
> >>* circular dependency checking: YMMV
> >>* reclaim-fs checking: which I knew how much developers need to
> >>conform to reclaim-fs, or what it is
> >
> >If there's XFS in the trace, then just post them. We try to fix
> >false positives (as well as real bugs) so lockdep reporting gets more
> >accurate and less noisy over time.
> >
> >Cheers,
> >
> >Dave.
> >
>
> Feel free to ignore and flame them as well. I'm going to make
> another attempt to triage my eldest Pentium 4, and there's a high
> chance that you'll have to reply, "Despite the xfs_* functions, that
> looks like a DRM issue. Go bug those guys."
>
> Thanks!
>
> Michael
>
> During generic/249 (lucky, first test out)...
> ======================================================
> [ INFO: possible circular locking dependency detected ]
> 3.9.0+ #2 Not tainted
> -------------------------------------------------------
> xfs_io/1181 is trying to acquire lock:
> (sb_writers#3){.+.+.+}, at: [<c10f01be>]
> generic_file_splice_write+0x7e/0x1b0
>
> but task is already holding lock:
> (&(&ip->i_iolock)->mr_lock){++++++}, at: [<c11dca9a>] xfs_ilock+0xea/0x190
Known issue. Needs VFS level changes to be fixed. I've posted
patches several times to linux-fsdevel over the past 2 years to fix
it, but I'm still waiting for them to be picked up....
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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