2008/9/16 Dave Chinner <david@xxxxxxxxxxxxx>: > 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..... Hi Dave Yes, you already explained a similar message to me, but it was a bug, not false positive. http://lkml.org/lkml/2008/7/3/29 http://lkml.org/lkml/2008/7/3/315 I will try to bisect. It is not a OOM case. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html