2008-11-14 13:56:33

by Alexander Beregalov

[permalink] [raw]
Subject: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
Modules linked in:
Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
Call Trace:
<IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
[<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
[<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
[<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
[<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
[<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
[<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
[<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
[<ffffffff803a6560>] elv_next_request+0x1d0/0x210
[<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
[<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
[<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
[<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
[<ffffffff803a8822>] blk_run_queue+0x21/0x35
[<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
[<ffffffff8043a33e>] scsi_next_command+0x36/0x46
[<ffffffff8043a509>] scsi_end_request+0x92/0xa4
[<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
[<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
[<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
[<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
[<ffffffff8023c173>] __do_softirq+0x70/0x101
[<ffffffff8020cc0c>] call_softirq+0x1c/0x28
[<ffffffff8020e229>] do_softirq+0x39/0x8a
[<ffffffff8023bd78>] irq_exit+0x45/0xa2
[<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
[<ffffffff8020bceb>] ret_from_intr+0x0/0xf
<EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
[<ffffffff80212e00>] ? mwait_idle+0x35/0x48
[<ffffffff8020a940>] ? cpu_idle+0x51/0xba
[<ffffffff80514f9c>] ? rest_init+0x70/0x72
---[ end trace 115cb4be7e150bb9 ]---


2008-11-15 16:09:32

by Jens Axboe

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

On Fri, Nov 14 2008, Alexander Beregalov wrote:
> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
> Modules linked in:
> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
> Call Trace:
> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
> [<ffffffff8023c173>] __do_softirq+0x70/0x101
> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
> [<ffffffff8020e229>] do_softirq+0x39/0x8a
> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
> ---[ end trace 115cb4be7e150bb9 ]---

I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
Is it reproducible in -next?

--
Jens Axboe

2008-11-15 17:26:23

by Alexander Beregalov

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

2008/11/15 Jens Axboe <[email protected]>:
> On Fri, Nov 14 2008, Alexander Beregalov wrote:
>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
>> Modules linked in:
>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
>> Call Trace:
>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
>> ---[ end trace 115cb4be7e150bb9 ]---
>
> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
Yes.
> Is it reproducible in -next?
I have seen it only once yet.

2008-11-17 15:39:34

by Alexander Beregalov

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

2008/11/15 Alexander Beregalov <[email protected]>:
> 2008/11/15 Jens Axboe <[email protected]>:
>> On Fri, Nov 14 2008, Alexander Beregalov wrote:
>>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
>>> Modules linked in:
>>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
>>> Call Trace:
>>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
>>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
>>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
>>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
>>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
>>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
>>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
>>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
>>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
>>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
>>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
>>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
>>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
>>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
>>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
>>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
>>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
>>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
>>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
>>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
>>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
>>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
>>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
>>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
>>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
>>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
>>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
>>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
>>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
>>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
>>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
>>> ---[ end trace 115cb4be7e150bb9 ]---
>>
>> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
> Yes.
>> Is it reproducible in -next?
> I have seen it only once yet.

I have the same warning on 2.6.28-rc5-next-20081117, reproducible on dbench.

2008-11-17 18:08:01

by Jens Axboe

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

On Mon, Nov 17 2008, Alexander Beregalov wrote:
> 2008/11/15 Alexander Beregalov <[email protected]>:
> > 2008/11/15 Jens Axboe <[email protected]>:
> >> On Fri, Nov 14 2008, Alexander Beregalov wrote:
> >>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
> >>> Modules linked in:
> >>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
> >>> Call Trace:
> >>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
> >>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
> >>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
> >>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
> >>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
> >>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
> >>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
> >>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
> >>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
> >>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
> >>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
> >>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
> >>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
> >>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
> >>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
> >>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
> >>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
> >>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
> >>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
> >>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
> >>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
> >>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
> >>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
> >>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
> >>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
> >>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
> >>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
> >>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
> >>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
> >>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
> >>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
> >>> ---[ end trace 115cb4be7e150bb9 ]---
> >>
> >> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
> > Yes.
> >> Is it reproducible in -next?
> > I have seen it only once yet.
>
> I have the same warning on 2.6.28-rc5-next-20081117, reproducible on dbench.

How big is the file system, how much ram do you have, what are your
mount options, how many dbench clients, and what dbench version? I tried
reproducing it today with no luck on -git + for-2.6.29.

--
Jens Axboe

2008-11-18 18:05:26

by Alexander Beregalov

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

2008/11/17 Jens Axboe <[email protected]>:
> On Mon, Nov 17 2008, Alexander Beregalov wrote:
>> 2008/11/15 Alexander Beregalov <[email protected]>:
>> > 2008/11/15 Jens Axboe <[email protected]>:
>> >> On Fri, Nov 14 2008, Alexander Beregalov wrote:
>> >>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
>> >>> Modules linked in:
>> >>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
>> >>> Call Trace:
>> >>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
>> >>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
>> >>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
>> >>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
>> >>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
>> >>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
>> >>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
>> >>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
>> >>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
>> >>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
>> >>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
>> >>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
>> >>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
>> >>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
>> >>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
>> >>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
>> >>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
>> >>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
>> >>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
>> >>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
>> >>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
>> >>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
>> >>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
>> >>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
>> >>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
>> >>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
>> >>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
>> >>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
>> >>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
>> >>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
>> >>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
>> >>> ---[ end trace 115cb4be7e150bb9 ]---
>> >>
>> >> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
>> > Yes.
>> >> Is it reproducible in -next?
>> > I have seen it only once yet.
>>
>> I have the same warning on 2.6.28-rc5-next-20081117, reproducible on dbench.
Bisected down to 70bfe2de81b32969db1b4939bf171bbe55bcf1ef
"elevator prevent flushing small requests to device"
>
> How big is the file system, how much ram do you have, what are your
> mount options, how many dbench clients, and what dbench version? I tried
> reproducing it today with no luck on -git + for-2.6.29.

/dev/root on / type xfs (rw,noatime,noquota)
/dev/root 145G
RAM 2G, Swap 3.9G
x86_64 SMP
dbench 3.0.4; 25 clients

2008-11-18 18:07:55

by Alexander Beregalov

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

2008/11/18 Alexander Beregalov <[email protected]>:
> 2008/11/17 Jens Axboe <[email protected]>:
>> On Mon, Nov 17 2008, Alexander Beregalov wrote:
>>> 2008/11/15 Alexander Beregalov <[email protected]>:
>>> > 2008/11/15 Jens Axboe <[email protected]>:
>>> >> On Fri, Nov 14 2008, Alexander Beregalov wrote:
>>> >>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
>>> >>> Modules linked in:
>>> >>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
>>> >>> Call Trace:
>>> >>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
>>> >>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
>>> >>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
>>> >>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
>>> >>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
>>> >>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
>>> >>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
>>> >>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
>>> >>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
>>> >>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
>>> >>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
>>> >>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
>>> >>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
>>> >>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
>>> >>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
>>> >>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
>>> >>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
>>> >>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
>>> >>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
>>> >>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
>>> >>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
>>> >>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
>>> >>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
>>> >>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
>>> >>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
>>> >>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
>>> >>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
>>> >>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
>>> >>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
>>> >>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
>>> >>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
>>> >>> ---[ end trace 115cb4be7e150bb9 ]---
>>> >>
>>> >> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
>>> > Yes.
>>> >> Is it reproducible in -next?
>>> > I have seen it only once yet.
>>>
>>> I have the same warning on 2.6.28-rc5-next-20081117, reproducible on dbench.
> Bisected down to 70bfe2de81b32969db1b4939bf171bbe55bcf1ef
> "elevator prevent flushing small requests to device"
forget: revert fixes it.
>>
>> How big is the file system, how much ram do you have, what are your
>> mount options, how many dbench clients, and what dbench version? I tried
>> reproducing it today with no luck on -git + for-2.6.29.
>
> /dev/root on / type xfs (rw,noatime,noquota)
> /dev/root 145G
> RAM 2G, Swap 3.9G
> x86_64 SMP
> dbench 3.0.4; 25 clients
>

2008-11-18 18:11:48

by Jens Axboe

[permalink] [raw]
Subject: Re: next-20081114: WARNING: at block/blk-barrier.c:246 blk_do_ordered()

On Tue, Nov 18 2008, Alexander Beregalov wrote:
> 2008/11/18 Alexander Beregalov <[email protected]>:
> > 2008/11/17 Jens Axboe <[email protected]>:
> >> On Mon, Nov 17 2008, Alexander Beregalov wrote:
> >>> 2008/11/15 Alexander Beregalov <[email protected]>:
> >>> > 2008/11/15 Jens Axboe <[email protected]>:
> >>> >> On Fri, Nov 14 2008, Alexander Beregalov wrote:
> >>> >>> WARNING: at block/blk-barrier.c:246 blk_do_ordered+0x22b/0x26a()
> >>> >>> Modules linked in:
> >>> >>> Pid: 0, comm: swapper Not tainted 2.6.28-rc4-next-20081114 #3
> >>> >>> Call Trace:
> >>> >>> <IRQ> [<ffffffff80236d63>] warn_on_slowpath+0x58/0x7d
> >>> >>> [<ffffffff802570e3>] ? mark_lock+0x1c/0x37a
> >>> >>> [<ffffffff803a69f9>] ? elv_rb_del+0x30/0x4b
> >>> >>> [<ffffffff803b1092>] ? cfq_remove_request+0x180/0x1d8
> >>> >>> [<ffffffff803afd03>] ? __cfq_slice_expired+0xd6/0xeb
> >>> >>> [<ffffffff803afd31>] ? cfq_slice_expired+0x19/0x1b
> >>> >>> [<ffffffff803b1832>] ? cfq_dispatch_requests+0x2c1/0x37e
> >>> >>> [<ffffffff803aa98c>] blk_do_ordered+0x22b/0x26a
> >>> >>> [<ffffffff803a6560>] elv_next_request+0x1d0/0x210
> >>> >>> [<ffffffff80439c7c>] scsi_request_fn+0x9e/0x539
> >>> >>> [<ffffffff80255c66>] ? put_lock_stats+0xe/0x27
> >>> >>> [<ffffffff803a827e>] blk_invoke_request_fn+0x3b/0x6e
> >>> >>> [<ffffffff803a87fd>] __blk_run_queue+0x25/0x29
> >>> >>> [<ffffffff803a8822>] blk_run_queue+0x21/0x35
> >>> >>> [<ffffffff80439509>] scsi_run_queue+0x2cf/0x379
> >>> >>> [<ffffffff8043a33e>] scsi_next_command+0x36/0x46
> >>> >>> [<ffffffff8043a509>] scsi_end_request+0x92/0xa4
> >>> >>> [<ffffffff8043aae7>] scsi_io_completion+0x1a7/0x3ad
> >>> >>> [<ffffffff80434551>] scsi_finish_command+0xe9/0xf2
> >>> >>> [<ffffffff8043afd5>] scsi_softirq_done+0x10e/0x117
> >>> >>> [<ffffffff803ac393>] blk_done_softirq+0x7f/0x8f
> >>> >>> [<ffffffff8023c173>] __do_softirq+0x70/0x101
> >>> >>> [<ffffffff8020cc0c>] call_softirq+0x1c/0x28
> >>> >>> [<ffffffff8020e229>] do_softirq+0x39/0x8a
> >>> >>> [<ffffffff8023bd78>] irq_exit+0x45/0xa2
> >>> >>> [<ffffffff8020e53a>] do_IRQ+0x16a/0x19c
> >>> >>> [<ffffffff8020bceb>] ret_from_intr+0x0/0xf
> >>> >>> <EOI> [<ffffffff80212e09>] ? mwait_idle+0x3e/0x48
> >>> >>> [<ffffffff80212e00>] ? mwait_idle+0x35/0x48
> >>> >>> [<ffffffff8020a940>] ? cpu_idle+0x51/0xba
> >>> >>> [<ffffffff80514f9c>] ? rest_init+0x70/0x72
> >>> >>> ---[ end trace 115cb4be7e150bb9 ]---
> >>> >>
> >>> >> I'm assuming this is new with -next and doesn't happen with 2.6.28-rc4?
> >>> > Yes.
> >>> >> Is it reproducible in -next?
> >>> > I have seen it only once yet.
> >>>
> >>> I have the same warning on 2.6.28-rc5-next-20081117, reproducible on dbench.
> > Bisected down to 70bfe2de81b32969db1b4939bf171bbe55bcf1ef
> > "elevator prevent flushing small requests to device"
> forget: revert fixes it.

That was my main culprit, thanks a lot for testing and taking the time
to bisect! I'll take a look at it and probably ask you to test a patch.

--
Jens Axboe