lkml.org 
[lkml]   [2011]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2.6.39-rc4+: Kernel leaking memory during FS scanning, regression?
On Wed, Apr 27, 2011 at 09:34:31PM +0200, Bruno Prémont wrote:
> On Wed, 27 April 2011 Pádraig Brady wrote:
> > On 27/04/11 19:41, Bruno Prémont wrote:
> > > On Wed, 27 April 2011 Bruno Prémont wrote:
> > >> On Wed, 27 Apr 2011 00:28:37 +0200 (CEST) Thomas Gleixner wrote:
> > >>> On Tue, 26 Apr 2011, Linus Torvalds wrote:
> > >>>> On Tue, Apr 26, 2011 at 10:09 AM, Bruno Prémont wrote:
> > >>>>> Just in case, /proc/$(pidof rcu_kthread)/status shows ~20k voluntary
> > >>>>> context switches and exactly one non-voluntary one.
> > >>>>>
> > >>>>> In addition when rcu_kthread has stopped doing its work
> > >>>>> `swapoff $(swapdevice)` seems to block forever (at least normal shutdown
> > >>>>> blocks on disabling swap device).
> > >
> > > Apparently it's not swapoff but `umount -a -t tmpfs` that's getting
> > > stuck here. Manual swapoff worked.

Doesn't "umount" wait for an RCU grace period? If so, then your hang
is just a consequence of RCU grace periods hanging, which in turn appears
to be a consequence of rcu_kthread not being allowed to run.

> > Anything to do with this?
> > http://thread.gmane.org/gmane.linux.kernel.mm/60953/
>
> I don't think so, if it is, it is only loosely related.
>
> From the trace you omitted to keep it's visible that it gets hit by
> non-operating RCU kthread.

Yep, makes sense!

Thanx, Paul

> Maybe existence of RCU barrier in this trace has some relation to
> above thread but I don't see it at first glance.
>
> [ 1714.960735] umount D 5a000040 5668 20331 20324 0x00000000
> [ 1714.960735] c3c99e5c 00000086 dd407900 5a000040 dd25a1a8 dd407900 dd25a120 c3c99e0c
> [ 1714.960735] c3c99e24 c10c1be2 c14d9f20 c3c99e5c c3c8c680 c3c8c680 000000bb c3c99e24
> [ 1714.960735] c10c0b88 dd25a120 dd407900 ddfd4b40 c3c99e4c ddfc9d20 dd402380 5a000010
> [ 1714.960735] Call Trace:
> [ 1714.960735] [<c10c1be2>] ? check_object+0x92/0x210
> [ 1714.960735] [<c10c0b88>] ? init_object+0x38/0x70
> [ 1714.960735] [<c10c1be2>] ? check_object+0x92/0x210
> [ 1714.960735] [<c13cb37d>] schedule_timeout+0x16d/0x280
> [ 1714.960735] [<c10c0b88>] ? init_object+0x38/0x70
> [ 1714.960735] [<c10c2122>] ? free_debug_processing+0x112/0x1f0
> [ 1714.960735] [<c10a3791>] ? shmem_put_super+0x11/0x20
> [ 1714.960735] [<c13cae9c>] wait_for_common+0x9c/0x150
> [ 1714.960735] [<c102c890>] ? try_to_wake_up+0x170/0x170
> [ 1714.960735] [<c13caff2>] wait_for_completion+0x12/0x20
> [ 1714.960735] [<c1075ad7>] rcu_barrier_sched+0x47/0x50
> ^^^^^^^^^^^^^^^^^
> [ 1714.960735] [<c104d3c0>] ? alloc_pid+0x370/0x370
> [ 1714.960735] [<c10ce74a>] deactivate_locked_super+0x3a/0x60
> [ 1714.960735] [<c10ce948>] deactivate_super+0x48/0x70
> [ 1714.960735] [<c10e7427>] mntput_no_expire+0x87/0xe0
> [ 1714.960735] [<c10e7800>] sys_umount+0x60/0x320
> [ 1714.960735] [<c10b231a>] ? remove_vma+0x3a/0x50
> [ 1714.960735] [<c10b3b22>] ? do_munmap+0x212/0x2f0
> [ 1714.960735] [<c10e7ad9>] sys_oldumount+0x19/0x20
> [ 1714.960735] [<c13cce10>] sysenter_do_call+0x12/0x26
>
> Bruno
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-04-28 00:07    [W:0.599 / U:0.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site