[WARNING] CPU: 27 PID: 6295 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()

[WARNING] CPU: 27 PID: 6295 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()

[Jinpu Wang]

Hi,

I hit WARNING below after update to 3.19-rc6, when I running fio with libaio.
Any one see this warning before, or maybe know how to fix it?

>From the call trace:
(gdb) list *read_events+0x1e8
0xffffffff81225ad8 is in read_events (fs/aio.c:1259).
1254         * something to be aware of when touching this code.
1255         */
1256        if (until.tv64 == 0)
1257            aio_read_events(ctx, min_nr, nr, event, &ret);
1258        else
1259            wait_event_interruptible_hrtimeout(ctx->wait,
1260                    aio_read_events(ctx, min_nr, nr, event, &ret),
1261                    until);
1262
1263        if (!ret && signal_pending(current))
(gdb)

looks like the WARNING come from wait_event_interruptible_hrtimeout?

[  165.011157] ------------[ cut here ]------------
[  165.011182] WARNING: CPU: 27 PID: 6295 at kernel/sched/core.c:7300
__might_sleep+0xbd/0xd0()
[  165.011197] do not call blocking ops when !TASK_RUNNING; state=1
set at [<ffffffff810d17f9>] prepare_to_wait_event+0x59/0x110
[  165.011199] Modules linked in: ibnbd_client(O) ibtrs_client(O)
ib_ipoib ib_uverbs ib_umad mlx4_ib mlx4_en null_blk rdma_cm iw_cm
ib_cm ib_sa ib_mad ib_core ib_addr mlx4_core
[  165.011224] CPU: 27 PID: 6295 Comm: fio Tainted: G           O
3.19.0-rc6debug #3
[  165.011226] Hardware name: Supermicro SBA-7142G-T4/BHQGE, BIOS 3.00
      10/24/2012
[  165.011228]  ffffffff81a56455 ffff88081173bc58 ffffffff817d232b
0000000000000007
[  165.011233]  ffff88081173bca8 ffff88081173bc98 ffffffff8109237a
ffff88081173bc88
[  165.011236]  ffffffff81a573d8 000000000000026d 0000000000000000
ffff881011e70000
[  165.011240] Call Trace:
[  165.011247]  [<ffffffff817d232b>] dump_stack+0x4c/0x65
[  165.011252]  [<ffffffff8109237a>] warn_slowpath_common+0x8a/0xc0
[  165.011255]  [<ffffffff810923f6>] warn_slowpath_fmt+0x46/0x50
[  165.011260]  [<ffffffff810daab5>] ? mark_held_locks+0x75/0xa0
[  165.011264]  [<ffffffff817d73b9>] ? mutex_lock_nested+0x289/0x3c0
[  165.011268]  [<ffffffff810d17f9>] ? prepare_to_wait_event+0x59/0x110
[  165.011271]  [<ffffffff810d17f9>] ? prepare_to_wait_event+0x59/0x110
[  165.011274]  [<ffffffff810bb6ed>] __might_sleep+0xbd/0xd0
[  165.011277]  [<ffffffff817d715f>] mutex_lock_nested+0x2f/0x3c0
[  165.011280]  [<ffffffff810c5a65>] ? local_clock+0x25/0x30
[  165.011284]  [<ffffffff817da7d6>] ? _raw_spin_unlock_irqrestore+0x36/0x60
[  165.011290]  [<ffffffff812255fc>] aio_read_events+0x4c/0x340
[  165.011293]  [<ffffffff810d1837>] ? prepare_to_wait_event+0x97/0x110
[  165.011296]  [<ffffffff81225ad8>] read_events+0x1e8/0x300
[  165.011300]  [<ffffffff810d1b60>] ? wait_woken+0xc0/0xc0
[  165.011305]  [<ffffffff810fa7c0>] ? __run_hrtimer+0x5e0/0x5e0
[  165.011308]  [<ffffffff81224d30>] ? lookup_ioctx+0x1c0/0x2a0
[  165.011312]  [<ffffffff81227982>] SyS_io_getevents+0x62/0x1a0
[  165.011317]  [<ffffffff813b490b>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[  165.011321]  [<ffffffff817db392>] system_call_fastpath+0x12/0x17
[  165.011323] ---[ end trace 5e2ce0c3bdb141cd ]---


Best Regards,

Jack Wang

Re: [WARNING] CPU: 27 PID: 6295 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()

[Cong Wang]

On Wed, Feb 4, 2015 at 1:57 AM, Jinpu Wang <jinpu.wang@profitbricks.com> wrote:
> Hi,
>
> I hit WARNING below after update to 3.19-rc6, when I running fio with libaio.
> Any one see this warning before, or maybe know how to fix it?
>
> From the call trace:
> (gdb) list *read_events+0x1e8
> 0xffffffff81225ad8 is in read_events (fs/aio.c:1259).
> 1254         * something to be aware of when touching this code.
> 1255         */
> 1256        if (until.tv64 == 0)
> 1257            aio_read_events(ctx, min_nr, nr, event, &ret);
> 1258        else
> 1259            wait_event_interruptible_hrtimeout(ctx->wait,
> 1260                    aio_read_events(ctx, min_nr, nr, event, &ret),
> 1261                    until);
> 1262
> 1263        if (!ret && signal_pending(current))
> (gdb)
>
> looks like the WARNING come from wait_event_interruptible_hrtimeout?

Probably fixed by:
http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=3e87523897e18a3e17fc8955ed795188be737ff1

Re: [WARNING] CPU: 27 PID: 6295 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()

[Jinpu Wang]

Thanks Cong,

I found another thread:
https://lkml.org/lkml/2015/2/3/690

Looks the patch fix the same WARNING.



On Thu, Feb 5, 2015 at 7:33 AM, Cong Wang <xiyou.wangcong@gmail.com> wrote:
> On Wed, Feb 4, 2015 at 1:57 AM, Jinpu Wang <jinpu.wang@profitbricks.com> wrote:
>> Hi,
>>
>> I hit WARNING below after update to 3.19-rc6, when I running fio with libaio.
>> Any one see this warning before, or maybe know how to fix it?
>>
>> From the call trace:
>> (gdb) list *read_events+0x1e8
>> 0xffffffff81225ad8 is in read_events (fs/aio.c:1259).
>> 1254         * something to be aware of when touching this code.
>> 1255         */
>> 1256        if (until.tv64 == 0)
>> 1257            aio_read_events(ctx, min_nr, nr, event, &ret);
>> 1258        else
>> 1259            wait_event_interruptible_hrtimeout(ctx->wait,
>> 1260                    aio_read_events(ctx, min_nr, nr, event, &ret),
>> 1261                    until);
>> 1262
>> 1263        if (!ret && signal_pending(current))
>> (gdb)
>>
>> looks like the WARNING come from wait_event_interruptible_hrtimeout?
>
> Probably fixed by:
> http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=3e87523897e18a3e17fc8955ed795188be737ff1



-- 
Mit freundlichen Grüßen,
Best Regards,

Jack Wang