Hi
More info about problem:
In my previous mail I wrote that I brought to call trace after a few
minutes but without use "dm snapshot: fix primary_pe race"and "wait for
chunks in destructor" of course and that one call trace ("after a few
minutes") involve problem with "wait for chunks in destructor".
But,yesterday I got next call trace:
Pid: 25597, comm: kcopyd Not tainted (2.6.27.7 #47)
EIP: 0060:[<c044d495>] EFLAGS: 00010282 CPU: 1
EIP is at remove_exception+0x5/0x20
EAX: c7b3d348 EBX: c7b3d348 ECX: 00200200 EDX: 00100100
ESI: c799d770 EDI: ea6a99c0 EBP: 00000000 ESP: f26b5ec0
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process kcopyd (pid: 25597, ti=f26b4000 task=f09e11f0 task.ti=f26b4000)
Stack: c044e04f 0000000c 00000000 f1980c40 00000000 c044f313 001396a7 00000000
000013ba 00000000 c7b3dd88 ea6a99c0 00000000 c044e100 c7b3dd88 f30f7aa8
00000000 c0449234 00000000 f30f7b94 00000400 00000000 00000000 ea53fcb8
Call Trace:
[<c044e04f>] pending_complete+0x9f/0x110
[<c044f313>] persistent_commit+0xe3/0x110
[<c044e100>] copy_callback+0x30/0x40
[<c0449234>] segment_complete+0x154/0x1d0
[<c0448e65>] run_complete_job+0x45/0x80
[<c04490e0>] segment_complete+0x0/0x1d0
[<c0448e20>] run_complete_job+0x0/0x80
[<c0449024>] process_jobs+0x14/0x70
[<c0449080>] do_work+0x0/0x40
[<c0449096>] do_work+0x16/0x40
[<c013502d>] run_workqueue+0x4d/0xf0
[<c013514d>] worker_thread+0x7d/0xc0
[<c01382e0>] autoremove_wake_function+0x0/0x30
[<c0526543>] __sched_text_start+0x1e3/0x4a0
[<c01382e0>] autoremove_wake_function+0x0/0x30
[<c0121a2b>] complete+0x2b/0x40
[<c01350d0>] worker_thread+0x0/0xc0
[<c0137db4>] kthread+0x44/0x70
[<c0137d70>] kthread+0x0/0x70
[<c0104c57>] kernel_thread_helper+0x7/0x10
=======================
Code: 4b 0c e8 cf ff ff ff 8b 56 08 8d 04 c2 8b 10 89 13 89 18 89 5a 04 89 43
04 5b 5e c3 8d 76 00 8d bc 27 00 00 00 00 8b 48 04 8b 10 <89> 11 89 4a 04 c7
00 00 01 10 00 c7 40 04 00 02 20 00 c3 90 8d
EIP: [<c044d495>] remove_exception+0x5/0x20 SS:ESP 0068:f26b5ec0
---[ end trace 8a6182ef9a00114f ]---
root@53434231:~# uname -a
Linux 53434231 2.6.27.7 #47 SMP Tue Nov 25 08:57:37 CET
2008 i686 GNU/Linux
root@53434231:~# addr2line -e ./vmlinux c044d495
include/linux/list.h:93
git log for my drivers/md/ show in order:
dm snapshot: wait for chunks in destructor
dm snapshot: fix register_snapshot deadlock
dm snapshot: drop unused last_percent
dm raid1: flush workqueue before destruction
md: fix bug in raid10 recovery.
md: linear: Fix a division by zero bug for very small arrays.
dm snapshot: fix primary_pe race
dm kcopyd: avoid queue shuffle
md: Fix rdev_size_store with size == 0
...
aluno3@xxxxxxxxxxxxxx wrote:
> Hi
>
>
> Yes, I am sure that I used 2.6.27.6. I checked it again.
>
> When I tested 2.6.27 without "dm snapshot: fix primary_pe race" I
> brought to call trace after a few minutes but with use "dm snapshot: fix
> primary_pe race" bring to call trace is very hard.Sometimes even after a
> few days test. I don`t have reproducible scenario :(. I tested kernel
> with use Bacula, Rsync, LVM, Snapshot together and very heavy load.It
> happened only 2 times through four weeks test.How can I help in this
> case? Thanks and best
>
>
> Mikulas Patocka wrote:
>
>> Hi
>>
>> This was supposed to be fixed with "dm snapshot: fix primary_pe race"
>> patch in 2.6.27.4. Are you sure that you really see it on 2.6.27.6? If so,
>> it looks like the bug wasn't fixed yet.
>>
>> How often does it happen? Do you have some reproducible scenario for this
>> bug?
>>
>> Mikulas
>>
>>
>>
>>> Hi
>>>
>>> I tested kernel 2.6.27.6 with patch from 2.6.28rc (wait for chunks in destructor,fix register_snapshot deadlock,) and I identified next problem with kernel and dm but repeatability this problem is very small.I got call trace:
>>>
>>>
>>> Pid: 26230, comm: kcopyd Not tainted (2.6.27.6 #36)
>>> EIP: 0060:[<c044d485>] EFLAGS: 00010282 CPU: 1
>>> EIP is at remove_exception+0x5/0x20
>>> EAX: ca3b5908 EBX: ca3b5908 ECX: 00200200 EDX: 00100100
>>> ESI: f7b489f8 EDI: e92ad980 EBP: 00000000 ESP: f29c7ec0
>>> DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
>>> Process kcopyd (pid: 26230, ti=f29c6000 task=e8512430 task.ti=f29c6000)
>>> Stack: c044e03f 0000000d 00000000 c85948c0 00000000 c044f2e7 0009bc30
>>> 00000000
>>> 0000e705 00000000 e8e41288 e92ad980 00000000 c044e0f0 e8e41288
>>> c7800ec8
>>> 00000000 c0449224 00000000 c7800fb4 00000400 00000000 00000000
>>> f2bdfbb0
>>> Call Trace:
>>> [<c044e03f>] pending_complete+0x9f/0x110
>>> [<c044f2e7>] persistent_commit+0xc7/0x110
>>> [<c044e0f0>] copy_callback+0x30/0x40
>>> [<c0449224>] segment_complete+0x154/0x1d0
>>> [<c0448e55>] run_complete_job+0x45/0x80
>>> [<c04490d0>] segment_complete+0x0/0x1d0
>>> [<c0448e10>] run_complete_job+0x0/0x80
>>> [<c0449014>] process_jobs+0x14/0x70
>>> [<c0449070>] do_work+0x0/0x40
>>> [<c0449086>] do_work+0x16/0x40
>>> [<c013502d>] run_workqueue+0x4d/0xf0
>>> [<c013514d>] worker_thread+0x7d/0xc0
>>> [<c01382e0>] autoremove_wake_function+0x0/0x30
>>> [<c0526583>] __sched_text_start+0x1e3/0x4a0
>>> [<c01382e0>] autoremove_wake_function+0x0/0x30
>>> [<c0121a2b>] complete+0x2b/0x40
>>> [<c01350d0>] worker_thread+0x0/0xc0
>>> [<c0137db4>] kthread+0x44/0x70
>>> [<c0137d70>] kthread+0x0/0x70
>>> [<c0104c57>] kernel_thread_helper+0x7/0x10
>>> =======================
>>> Code: 4b 0c e8 cf ff ff ff 8b 56 08 8d 04 c2 8b 10 89 13 89 18 89 5a 04
>>> 89 43 04 5b 5e c3 8d 76 00 8d bc 27 00 00 00 00 8b 48 04 8b 10 <89> 11
>>> 89 4a 04 c7 00 00 01 10 00 c7 40 04 00 02 20 00 c3 90 8d
>>> EIP: [<c044d485>] remove_exception+0x5/0x20 SS:ESP 0068:f29c7ec0
>>> ---[ end trace 834a1d3742a1be05 ]---
>>>
>>>
>>>
>>> addr2line returned include/linux/list.h:93 for EIP c044d485:
>>>
>>>
>>> static inline void __list_del(struct list_head * prev, struct list_head
>>> * next)
>>> {
>>> next->prev = prev;
>>> prev->next = next; //line 93
>>> }
>>>
>>>
>>>
>>>
>>> A few weeks ago I got similar call trace with plain kernel 2.6.27 and
>>> patches from mail thread:
>>>
>>>
>>> BUG: unable to handle kernel paging request at 00200200
>>> IP: [<c044bf65>] remove_exception+0x5/0x20
>>> *pdpt = 0000000029acc001 *pde = 0000000000000000
>>> Oops: 0002 [#1] SMP
>>> Modules linked in: iscsi_trgt mptctl mptbase st sg drbd bonding
>>> iscsi_tcp libiscsi scsi_transport_iscsi aacraid sata_nv forcedeth button
>>> ftdi_sio usbserial
>>>
>>> Pid: 31375, comm: kcopyd Not tainted (2.6.27 #21)
>>> EIP: 0060:[<c044bf65>] EFLAGS: 00010282 CPU: 1
>>> EIP is at remove_exception+0x5/0x20
>>> EAX: f276da88 EBX: f276da88 ECX: 00200200 EDX: 00100100
>>> ESI: c79a4a58 EDI: c9268cc0 EBP: 00000000 ESP: ecbcbec0
>>> DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
>>> Process kcopyd (pid: 31375, ti=ecbca000 task=e6d9d220 task.ti=ecbca000)
>>> Stack: c044cb1f 0000000e 00000000 c916b480 00000000 c044dde3 00018f47
>>> 00000000
>>> 00002870 00000000 c70cba48 c9268cc0 00000000 c044cbd0 c70cba48
>>> c720aec8
>>> 00000000 c0447d04 00000000 c720afb4 00000400 00000000 00000000
>>> efc65580
>>> Call Trace:
>>> [<c044cb1f>] pending_complete+0x9f/0x110
>>> [<c044dde3>] persistent_commit+0xe3/0x110
>>> [<c044cbd0>] copy_callback+0x30/0x40
>>> [<c0447d04>] segment_complete+0x154/0x1d0
>>> [<c0447935>] run_complete_job+0x45/0x80
>>> [<c0447bb0>] segment_complete+0x0/0x1d0
>>> [<c04478f0>] run_complete_job+0x0/0x80
>>> [<c0447af4>] process_jobs+0x14/0x70
>>> [<c0447b50>] do_work+0x0/0x40
>>> [<c0447b66>] do_work+0x16/0x40
>>> [<c013509d>] run_workqueue+0x4d/0xf0
>>> [<c01351bd>] worker_thread+0x7d/0xc0
>>> [<c0138350>] autoremove_wake_function+0x0/0x30
>>> [<c0524f2c>] __sched_text_start+0x1ec/0x4b0
>>> [<c0138350>] autoremove_wake_function+0x0/0x30
>>> [<c0121a9b>] complete+0x2b/0x40
>>> [<c0135140>] worker_thread+0x0/0xc0
>>> [<c0137e24>] kthread+0x44/0x70
>>> [<c0137de0>] kthread+0x0/0x70
>>> [<c0104c57>] kernel_thread_helper+0x7/0x10
>>> =======================
>>> Code: 4b 0c e8 cf ff ff ff 8b 56 08 8d 04 c2 8b 10 89 13 89 18 89 5a 04
>>> 89 43 04 5b 5e c3 8d 76 00 8d bc 27 00 00 00 00 8b 48 04 8b 10 <89> 11
>>> 89 4a 04 c7 00 00 01 10 00 c7 40 04 00 02 20 00 c3 90 8d
>>> EIP: [<c044bf65>] remove_exception+0x5/0x20 SS:ESP 0068:ecbcbec0
>>> ---[ end trace 25afcedfe7eb0a2b ]---
>>>
>>> Is this known problem or something new? Thanks
>>>
>>>
>>> Mikulas Patocka wrote:
>>>
>>>
>>>> On Thu, 23 Oct 2008, aluno3@xxxxxxxxxxxxxx wrote:
>>>>
>>>>
>>>>
>>>>
>>>>> I used dm-snapshot-fix-primary-pe-race.patch and last patch related with
>>>>> pending_exception.After the same test and workload everything work
>>>>> correctly so far.Is it final patch?
>>>>>
>>>>>
>>>>>
>>>> Yes, these two patches are expected to be the final fix. Thanks for the
>>>> testing. If you get some more crashes even with these two, write about
>>>> them.
>>>>
>>>> Mikulas
>>>>
>>>>
>>>>
>>>>
>>>>> best and thanks
>>>>>
>>>>>
>>>>> Mikulas Patocka wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Oh, sorry for this "struct struct" in the patch in free_pending_exception,
>>>>>> replace it just with one "struct". I forgot to refresh the patch before
>>>>>> sending it.
>>>>>>
>>>>>> Mikulas
>>>>>>
>>>>>> On Wed, 22 Oct 2008, Mikulas Patocka wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> On Wed, 22 Oct 2008, aluno3@xxxxxxxxxxxxxx wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> Hi
>>>>>>>>
>>>>>>>> I used your patch and I ran test the same workload. After a few hours
>>>>>>>> test, everything is OK. Is it possible? Test is still running.When I get
>>>>>>>> something wrong from kernel I write to You again.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> Hi
>>>>>>>
>>>>>>> That's good that it works. So try this. Keep the first patch (it is this
>>>>>>> one ---
>>>>>>> http://people.redhat.com/mpatocka/patches/kernel/2.6.27/dm-snapshot-fix-primary-pe-race.patch
>>>>>>> --- I think Milan already sent it to you and you have it applied). Undo
>>>>>>> the second patch (that one that hides deallocation with /* */ ). And apply
>>>>>>> this. Run the same test.
>>>>>>>
>>>>>>> Mikulas
>>>>>>>
>>>>>>> ---
>>>>>>> drivers/md/dm-snap.c | 10 +++++++++-
>>>>>>> drivers/md/dm-snap.h | 2 ++
>>>>>>> 2 files changed, 11 insertions(+), 1 deletion(-)
>>>>>>>
>>>>>>> Index: linux-2.6.27-clean/drivers/md/dm-snap.c
>>>>>>> ===================================================================
>>>>>>> --- linux-2.6.27-clean.orig/drivers/md/dm-snap.c 2008-10-22 15:41:24.000000000 +0200
>>>>>>> +++ linux-2.6.27-clean/drivers/md/dm-snap.c 2008-10-22 15:51:33.000000000 +0200
>>>>>>> @@ -368,6 +368,7 @@ static struct dm_snap_pending_exception
>>>>>>> struct dm_snap_pending_exception *pe = mempool_alloc(s->pending_pool,
>>>>>>> GFP_NOIO);
>>>>>>>
>>>>>>> + atomic_inc(&s->n_pending_exceptions);
>>>>>>> pe->snap = s;
>>>>>>>
>>>>>>> return pe;
>>>>>>> @@ -375,7 +376,10 @@ static struct dm_snap_pending_exception
>>>>>>>
>>>>>>> static void free_pending_exception(struct dm_snap_pending_exception *pe)
>>>>>>> {
>>>>>>> - mempool_free(pe, pe->snap->pending_pool);
>>>>>>> + struct struct dm_snapshot *s = pe->snap;
>>>>>>> + mempool_free(pe, s->pending_pool);
>>>>>>> + smp_mb__before_atomic_dec();
>>>>>>> + atomic_dec(&s->n_pending_exceptions);
>>>>>>> }
>>>>>>>
>>>>>>> static void insert_completed_exception(struct dm_snapshot *s,
>>>>>>> @@ -601,6 +605,7 @@ static int snapshot_ctr(struct dm_target
>>>>>>> s->valid = 1;
>>>>>>> s->active = 0;
>>>>>>> s->last_percent = 0;
>>>>>>> + atomic_set(&s->n_pending_exceptions, 0);
>>>>>>> init_rwsem(&s->lock);
>>>>>>> spin_lock_init(&s->pe_lock);
>>>>>>> s->ti = ti;
>>>>>>> @@ -727,6 +732,9 @@ static void snapshot_dtr(struct dm_targe
>>>>>>> /* After this returns there can be no new kcopyd jobs. */
>>>>>>> unregister_snapshot(s);
>>>>>>>
>>>>>>> + while (atomic_read(&s->n_pending_exceptions))
>>>>>>> + yield();
>>>>>>> +
>>>>>>> #ifdef CONFIG_DM_DEBUG
>>>>>>> for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)
>>>>>>> BUG_ON(!hlist_empty(&s->tracked_chunk_hash[i]));
>>>>>>> Index: linux-2.6.27-clean/drivers/md/dm-snap.h
>>>>>>> ===================================================================
>>>>>>> --- linux-2.6.27-clean.orig/drivers/md/dm-snap.h 2008-10-22 15:45:08.000000000 +0200
>>>>>>> +++ linux-2.6.27-clean/drivers/md/dm-snap.h 2008-10-22 15:46:49.000000000 +0200
>>>>>>> @@ -163,6 +163,8 @@ struct dm_snapshot {
>>>>>>>
>>>>>>> mempool_t *pending_pool;
>>>>>>>
>>>>>>> + atomic_t n_pending_exceptions;
>>>>>>> +
>>>>>>> struct exception_table pending;
>>>>>>> struct exception_table complete;
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> dm-devel mailing list
>>>>>>> dm-devel@xxxxxxxxxx
>>>>>>> https://www.redhat.com/mailman/listinfo/dm-devel
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>
>>>>
>>>>
>>
>>
>
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>
>
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