From: Jeff Layton <jeff.layton@primarydata.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trondmy@gmail.com>, linux-nfs@vger.kernel.org
Subject: Re: schedule WARNING from nfs41_callback_svc
Date: Mon, 5 Jan 2015 14:08:04 -0800 [thread overview]
Message-ID: <20150105140804.0185ae17@synchrony.poochiereds.net> (raw)
In-Reply-To: <20150105140003.0ddd42a2@synchrony.poochiereds.net>
On Mon, 5 Jan 2015 14:00:03 -0800
Jeff Layton <jlayton@primarydata.com> wrote:
> On Mon, 5 Jan 2015 15:20:26 -0500
> "J. Bruce Fields" <bfields@fieldses.org> wrote:
>
> > On 3.19-rc2 I'm getting:
> >
> > [ 426.715480] WARNING: CPU: 2 PID: 7920 at kernel/sched/core.c:7303 __might_sleep+0x92/0xa0()
> > [ 426.715485] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff810ad99f>] prepare_to_wait+0x2f/0x90
> > ...
> > [ 426.715613] [<ffffffff81094eb4>] groups_alloc+0x34/0x110
> > [ 426.715638] [<ffffffffa00181da>] svcauth_unix_accept+0x14a/0x280 [sunrpc]
> > [ 426.715659] [<ffffffffa00170a8>] svc_authenticate+0xc8/0xe0 [sunrpc]
> > [ 426.715683] [<ffffffffa0012cf2>] svc_process_common+0x202/0x6d0 [sunrpc]
> > [ 426.715703] [<ffffffffa00135d8>] bc_svc_process+0x1c8/0x260 [sunrpc]
> > [ 426.715725] [<ffffffffa01da8e0>] nfs41_callback_svc+0x100/0x1b0 [nfsv4]
> > ...
> >
> > Looks like this is a new check added by 8eb23b9f35aa "sched: Debug
> > nested sleeps". I don't *think* it's catching a real problem here, but
> > maybe I'm missing some subtlety. I suppose nfs41_callback_svc() could
> > move the finish_wait() so it's done before the bc_svc_process()?
> >
>
> Yeah, the current code looks quite goofy. We really shouldn't be doing
> all of the bc_svc_process stuff while in TASK_INTERRUPTIBLE. Doing what
> you suggest looks like the right fix to me.
>
...and while we're on the subject...
Why is nfs41_callback_svc sleeping in TASK_INTERRUPTIBLE anyway? Do we
expect that kthread to receive signals? If not, perhaps we should go
ahead and switch that over to TASK_UNINTERRUPTIBLE instead?
--
Jeff Layton <jlayton@primarydata.com>
prev parent reply other threads:[~2015-01-05 22:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-05 20:20 schedule WARNING from nfs41_callback_svc J. Bruce Fields
2015-01-05 22:00 ` Jeff Layton
2015-01-05 22:08 ` Jeff Layton [this message]
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