Re: XFS hung on 2.6.33.3 kernel

[Ilia Mirkin <imirkin@xxxxxxxxxxxx>]

On Wed, Aug 4, 2010 at 12:27 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> On Tue, Aug 03, 2010 at 09:15:53PM -0400, Ilia Mirkin wrote:
>> On Tue, Aug 3, 2010 at 8:47 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
>> > Ilia,
>> >
>> > Can you send me the output of this for your kernel that the
>> > traces came from:
>> >
>> > $ gdb <path/to/vmlinux>
>> > (gdb) l *( xfs_write+0x2cc)
>> >
>> > You can run it against the vmlinux file in the kernel build
>> > directory.  Basically I need to know which xfs_ilock() call in
>> > xfs_write() one of the mysqld-test processes is stuck on.
>>
>> No problem - BTW, I'm running this on a 2.6.33.3 kernel (same as the
>> one before, although diff hardware). If you want (and are fine with me
>> "destroying" the current state), I can upgrade it to a kernel of your
>> choice and repeat the test overnight.
>>
>> Naturally I didn't have CONFIG_DEBUG_INFO in there... just changed
>> that to Y and recompiled. I'm not entirely sure that this preserves
>> all the offsets, but at least the BUG-HUNTING doc makes allusions that
>> it would.
>>
>> (gdb) l *( xfs_write+0x2cc)
>> 0xffffffff8124342d is in xfs_write (fs/xfs/linux-2.6/xfs_lrw.c:597).
>> 592                     if (!need_i_mutex && (mapping->nrpages || pos
>> > xip->i_size)) {
>> 593                             xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
>> 594                             iolock = XFS_IOLOCK_EXCL;
>> 595                             need_i_mutex = 1;
>> 596                             mutex_lock(&inode->i_mutex);
>> 597                             xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
>
> Make sense. Can you run 'l *(xfs_ilock+0x2c)' as well? I just need to
> confirm which lock it has blocked on.

(gdb) l *(xfs_ilock+0x2c)
0xffffffff81221001 is in xfs_ilock (fs/xfs/linux-2.6/mrlock.h:48).
43              down_read_nested(&mrp->mr_lock, subclass);
44      }
45
46      static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
47      {
48              down_write_nested(&mrp->mr_lock, subclass);
49      #ifdef DEBUG
50              mrp->mr_writer = 1;
51      #endif
52      }