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Date: Wed, 29 Oct 2014 18:13:45 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>, LKP <lkp@01.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "oleg@redhat.com" <oleg@redhat.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        David Miller <davem@davemloft.net>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>
Subject: Re: [PATCH] netdev: Fix sleeping inside wait event
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On Wed, Oct 29, 2014 at 09:29:55AM -0700, Cong Wang wrote:
> (Adding netdev@...)
> 
> On Wed, Oct 29, 2014 at 9:16 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > Dave, this relies on bits currently in tip/sched/core, if you're ok I'll
> > merge it through that tree.
> >
> > ---
> > Subject: netdev: Fix sleeping inside wait event
> > From: Peter Zijlstra <peterz@infradead.org>
> > Date: Wed Oct 29 17:04:56 CET 2014
> >
> > rtnl_lock_unregistering() takes rtnl_lock() -- a mutex -- inside a
> > wait loop. The wait loop relies on current->state to function, but so
> > does mutex_lock(), nesting them makes for the inner to destroy the
> > outer state.
> >
> 
> While you are on it, please fix rtnl_lock_unregistering_all() too?

Ah, that's hidden someplace else, sure I can do that. Thanks for
pointing it out.