Date: Mon, 22 Jun 2009 10:04:53 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Cc: Rabin Vincent <rabin@rab.in>, Ingo Molnar <mingo@elte.hu>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: BUG: scheduling while atomic
Message-ID: <20090622100453.2a1bde3b@lxorguk.ukuu.org.uk>
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	<20090620174320.GA6791@debian>
	<20090620185452.GD3138@localdomain.by>
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On Sat, 20 Jun 2009 21:54:52 +0300
Sergey Senozhatsky <sergey.senozhatsky@mail.by> wrote:

> On (06/20/09 23:13), Rabin Vincent wrote:
> > On Fri, Jun 19, 2009 at 09:15:29PM +0300, Sergey Senozhatsky wrote:
> > > Hello.
> > > I see lots of "BUG: scheduling while atomic" with current kernels (started with 2.6.30-git1, 2.6.30 is ok).
> > > For example (2.6.30-git14):
> > 
> > Looks like the net softirq (via ppp) ends up calling tty_throttle(), and
> > this causes problems because of the mutex_lock() added there by
> > 38db8979.  I've cc'd the tty maintainer.

Looks like we caught another naughty. It's not safe to call the
throttle/unthrottle methods from an IRQ path, never really has been as
they can be things like USB drivers that need to send USB messages and
sleep when that happens.

Alan
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