Re: [RFC][PATCH 0/7] nested sleeps, fixes and debug infra

[Peter Zijlstra]

On Wed, Aug 06, 2014 at 02:16:03PM -0700, David Miller wrote:
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Date: Wed, 6 Aug 2014 10:31:34 +0200
> 
> > On Wed, Aug 06, 2014 at 11:51:29AM +0400, Ilya Dryomov wrote:
> > 
> >> OK, this one is a bit different.
> >> 
> >> WARNING: CPU: 1 PID: 1744 at kernel/sched/core.c:7104 __might_sleep+0x58/0x90()
> >> do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff81070e10>] prepare_to_wait+0x50 /0xa0
> > 
> >>  [<ffffffff8105bc38>] __might_sleep+0x58/0x90
> >>  [<ffffffff8148c671>] lock_sock_nested+0x31/0xb0
> >>  [<ffffffff81498aaa>] sk_stream_wait_memory+0x18a/0x2d0
> > 
> > Urgh, tedious. Its not an actual bug as is. Due to the condition check
> > in sk_wait_event() we can call lock_sock() with ->state != TASK_RUNNING.
> > 
> > I'm not entirely sure what the cleanest way is to make this go away.
> > Possibly something like so:
> 
> If you submit this formally to netdev with a signoff I'm willing to apply
> this if it helps the debug infrastructure.

Thanks, for now I'm just collecting things to see how far I can take
this. But I'll certainly include you and netdev on a next posting.

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