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From: Javier Cardona <javier@cozybit.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: "John W. Linville" <linville@tuxdriver.com>,
	linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH] mac80211: fix and simplify mesh locking
Date: Wed, 18 May 2011 18:40:33 -0700	[thread overview]
Message-ID: <BANLkTi=0RMrBKVFFC7UUnVPyZpZvfGvK6g@mail.gmail.com> (raw)
In-Reply-To: <1305758752.8827.1.camel@jlt3.sipsolutions.net>

On Wed, May 18, 2011 at 3:45 PM, Johannes Berg
<johannes@sipsolutions.net> wrote:
> On Tue, 2011-05-17 at 16:05 -0700, Javier Cardona wrote:
>
>> I'm seeing this after trying your patch, probably because the
>> allocations mesh_table_alloc() can block.  In the past I had tried to
>> allocate the table before entering the critical section.  If that is
>> not possible for the race condition you mention,  then I guess we'll
>> have to make those allocations GFP_ATOMIC?
>
> Err, now I'm confused, how could the code have done non-atomic
> allocations while under rcu_read_lock()? I guess there was just no
> verification there?

I'm not sure.  I can tell you that the bug message is only triggered
after your patch was applied, same .config.
Maybe i have an rcu configuration that does not check that.

Is making the allocations atomic an acceptable solution?

Javier

  reply	other threads:[~2011-05-19  1:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-14  9:00 [PATCH] mac80211: fix and simplify mesh locking Johannes Berg
2011-05-14  9:20 ` Johannes Berg
2011-05-17 23:05   ` Javier Cardona
2011-05-17 23:13     ` [PATCH] mac80211: Don't sleep when growing the mesh path Javier Cardona
2011-05-18 22:45     ` [PATCH] mac80211: fix and simplify mesh locking Johannes Berg
2011-05-19  1:40       ` Javier Cardona [this message]
2011-05-19  4:14         ` Johannes Berg

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