From: Ben Greear <greearb@candelatech.com>
To: "Luis R. Rodriguez" <mcgrof@gmail.com>
Cc: linux-wireless@vger.kernel.org
Subject: Re: [PATCH] mac80211: Fix deadlock in ieee80211_do_stop.
Date: Fri, 12 Nov 2010 12:16:06 -0800 [thread overview]
Message-ID: <4CDDA086.2010803@candelatech.com> (raw)
In-Reply-To: <AANLkTin_qaMO+3Zm3qnqZ2WDjLoujvCa0W2eLO1BT_Ti@mail.gmail.com>
On 11/12/2010 12:08 PM, Luis R. Rodriguez wrote:
> On Fri, Nov 12, 2010 at 12:07 PM,<greearb@candelatech.com> wrote:
>> From: Ben Greear<greearb@candelatech.com>
>>
>> We cannot call flush_work here because we are holding
>> RTNL and the worker thread(s) that will be called upon to
>> do the flushing might already be running a piece of work
>> that is blocking on RTNL. That leads to deadlock and/or
>> OOM.
>>
>> The ieee80211_iface_work method does nothing when sdata
>> is stopped (as it would be when the flush_work was called)
>> so it shouldn't be any big change to just cancel the work
>> entirely.
>>
>> Signed-off-by: Ben Greear<greearb@candelatech.com>
>
> Is this a stable fix?
We didn't see this when testing against .36-ish
wireless-testing...
I can't do any useful testing against official .36 since it
doesn't have the ath5k multi-vif support.
I'm also not sure this patch 100% right, though
it does fix a very reproducible bug for me. I might be
missing some side-affect of cancelling instead of attempting
to flush the work queue, however, so we should wait for
input from whoever wrote that code in the first place...
Thanks,
Ben
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2010-11-12 20:16 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-12 20:07 [PATCH] mac80211: Fix deadlock in ieee80211_do_stop greearb
2010-11-12 20:08 ` Luis R. Rodriguez
2010-11-12 20:16 ` Ben Greear [this message]
2010-11-12 20:49 ` Johannes Berg
2010-11-12 20:57 ` Ben Greear
2010-11-12 21:08 ` Johannes Berg
2010-11-12 21:51 ` Ben Greear
2010-11-13 10:34 ` Tejun Heo
2010-11-15 21:16 ` Ben Greear
2010-11-16 14:19 ` Tejun Heo
2010-11-16 16:51 ` Ben Greear
2010-11-17 8:55 ` Tejun Heo
2010-11-17 17:37 ` Ben Greear
2010-11-16 17:40 ` Johannes Berg
2010-11-17 8:47 ` Tejun Heo
2010-11-17 18:53 ` Johannes Berg
2010-11-17 18:59 ` Ben Greear
2010-11-17 19:03 ` Johannes Berg
2010-11-18 6:34 ` Tejun Heo
2010-11-18 7:07 ` Johannes Berg
2010-11-18 7:22 ` Tejun Heo
2010-11-18 16:59 ` Johannes Berg
2010-11-19 14:34 ` Tejun Heo
2010-11-19 17:57 ` Johannes Berg
2010-11-19 20:55 ` Ben Greear
2010-11-19 22:27 ` Luis R. Rodriguez
2010-12-08 17:36 ` Ben Greear
2010-12-08 18:19 ` Ben Greear
2010-12-08 18:28 ` Ben Greear
2010-12-09 14:34 ` Tejun Heo
2010-12-09 14:42 ` Johannes Berg
2010-12-09 14:46 ` Tejun Heo
2010-12-09 16:17 ` Tejun Heo
[not found] ` <4D0156F6.4000306@candelate ch.com>
2010-12-09 17:27 ` Ben Greear
2010-12-09 22:23 ` Ben Greear
2010-12-10 15:11 ` Tejun Heo
2010-12-10 16:35 ` Ben Greear
2010-11-18 17:55 ` Ben Greear
2010-11-18 18:04 ` Tejun Heo
2010-11-18 18:11 ` Ben Greear
2010-11-17 20:13 ` Ben Greear
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