Messages in this thread | | | From | Grant Coady <> | Subject | Re: 2.6.27-rc6: lockdep warning: iprune_mutex at shrink_icache_memory+0x38/0x1a8 | Date | Tue, 16 Sep 2008 14:31:05 +1000 |
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On Tue, 16 Sep 2008 12:52:04 +1000, Dave Chinner <david@fromorbit.com> wrote:
>On Sun, Sep 14, 2008 at 03:31:38AM +0400, Alexander Beregalov wrote: >> Hi >> >> [ INFO: possible circular locking dependency detected ] >> 2.6.27-rc6-00034-gd1c6d2e #3 >> ------------------------------------------------------- >> nfsd/1766 is trying to acquire lock: >> (iprune_mutex){--..}, at: [<c01743fb>] shrink_icache_memory+0x38/0x1a8 >> >> but task is already holding lock: >> (&(&ip->i_iolock)->mr_lock){----}, at: [<c021134f>] >> xfs_ilock+0xa2/0xd6 >> >> >> I read files through nfs and saw delay for few seconds. >> System is x86_32, nfs, xfs. >> The last working kernel is 2.6.27-rc5, >> I do not know yet is it reproducible or not. > ><sigh> > >We need a FAQ for this one. It's a false positive. Google for an >explanation - I've explained it 4 or 5 times in the past year and >asked that the lockdep folk invent a special annotation for the >iprune_mutex (or memory reclaim) because of the way it can cause >recursion into the filesystem and hence invert lock orders without >causing deadlocks.....
Yeah, but a 30 second dreadlock? It's a long wait wondering what's gone down or not ;)
Grant.
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