* Re: "BUG: held lock freed!" lock validator tripped by kswapd & xfs
[not found] ` <feed8cdd0612011434n4c025fcbvd9997485d8b35149@mail.gmail.com>
@ 2006-12-04 1:35 ` David Chinner
0 siblings, 0 replies; only message in thread
From: David Chinner @ 2006-12-04 1:35 UTC (permalink / raw)
To: Stephen Pollei; +Cc: Mike Mattie, linux-kernel @ vger. kernel. org, xfs
On Fri, Dec 01, 2006 at 02:34:42PM -0800, Stephen Pollei wrote:
> On 12/1/06, Mike Mattie <codermattie@gmail.com> wrote:
>
> >In an attempt to debug another kernel issue I turned on the lock validator
> >and
> >managed to generate this report.
> >
> >As a side note the first attempt to boot with the lock validator failed
> >with
> >a message indicating I had exceeded MAX_LOCK_DEPTH. To get this trace
> >I patched sched.h: MAX_LOCK_DEPTH to 60.
> >
> >Dec 1 08:35:41 reforged [ 3052.513931] =========================
> >Dec 1 08:35:41 reforged [ 3052.513937] [ BUG: held lock freed! ]
> >Dec 1 08:35:41 reforged [ 3052.513939] -------------------------
> >Dec 1 08:35:41 reforged [ 3052.513943] kswapd0/183 is freeing memory
> >c3458000-c3458fff, with a lock still held there! Dec 1 08:35:41
> >reforged [ 3052.513947] (&(&ip->i_iolock)->mr_lock){....}, at:
> >[<c0222289>] xfs_ilock+0x20/0x75 Dec 1 08:35:41 reforged
> >[ 3052.513959] 28 locks held by kswapd0/183: Dec 1 08:35:41 reforged
> >[ 3052.513961] #0: (&(&ip->i_iolock)->mr_lock){....}, at:
> >[<c0222289>] xfs_ilock+0x20/0x75 Dec 1 08:35:41 reforged
> >[ 3052.513968] #1: (&(&ip->i_lock)->mr_lock){....}, at: [<c02222bb>]
> >xfs_ilock+0x52/0x75 Dec 1 08:35:41 reforged [ 3052.513975]
>
> seems to alternate between same two locks. But both c0222289 and
> c02222bb are not between the page(oxfff=4095 or about 4k) which kswapd
> is trying to get rid of.
> I think this trace is on crack somehow.
IIRC, lockdep doesn't understand the xfs inode locks yet. We've
got a patch to fix most of this, but I don't think it's been merged.
Cheers,
Dave
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
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