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Date: Fri, 27 Mar 2009 14:05:02 -0500
From: Larry Finger <Larry.Finger@lwfinger.net>
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To: Jonathan Corbet <corbet@lwn.net>
CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
       LKML <linux-kernel@vger.kernel.org>, Christoph Hellwig <hch@lst.de>,
       Al Viro <viro@zeniv.linux.org.uk>, Li Zefan <lizf@cn.fujitsu.com>,
       Wu Fengguang <fengguang.wu@intel.com>, Ingo Molnar <mingo@elte.hu>
Subject: Re: Possible IRQ lock inversion from 2.6.29-Linus-03321-gbe0ea69
 (2.6.29-git)
References: <49CC5F15.4020404@lwfinger.net> <200903271354.45480.bzolnier@gmail.com> <20090327120623.3056c795@bike.lwn.net>
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Jonathan Corbet wrote:
> 
> We could do that.  When I made the change I'd verified that there were
> no users in IRQ context, and I couldn't really see why there should
> be.  I'd rather avoid adding all those IRQ disables if I can avoid it.
> 
> How about, instead, just reversing the order of lock acquisition in
> fasync_helper()?  That would increase the hold time for f_lock, but I
> have a hard time seeing that being a real problem.  I'm running with
> the following now; all seems well.  I'll send it up in a bit if nobody
> gripes.

The patch gets rid of the warning for me.

Larry