From: "John W. Linville" <linville@tuxdriver.com>
To: Eliad Peller <eliad@wizery.com>
Cc: Michal Hocko <mhocko@suse.cz>,
Stanislaw Gruszka <sgruszka@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-wireless@vger.kernel.org,
Yong Zhang <yong.zhang0@gmail.com>
Subject: Re: [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta
Date: Thu, 1 Dec 2011 10:45:30 -0500 [thread overview]
Message-ID: <20111201154530.GA24074@tuxdriver.com> (raw)
In-Reply-To: <CAB3XZEd1D7mR3Q_vweNHYUbZxmywbMi3FomQbdSy=1DB8Y0KzA@mail.gmail.com>
On Thu, Dec 01, 2011 at 04:23:19PM +0200, Eliad Peller wrote:
> On Thu, Dec 1, 2011 at 4:05 PM, Michal Hocko <mhocko@suse.cz> wrote:
> > On Thu 01-12-11 13:44:40, Michal Hocko wrote:
> >> On Thu 01-12-11 12:59:12, Stanislaw Gruszka wrote:
> >> > On Thu, Dec 01, 2011 at 11:55:38AM +0100, Michal Hocko wrote:
> >> > > [ 349.316070] iwl3945_rs_free_sta rs_sta f4be1ac0
> >> > > [ 349.316076] ------------[ cut here ]------------
> >> > > [ 349.316097] WARNING: at drivers/net/wireless/iwlegacy/iwl-3945-rs.c:438 iwl3945_rs_free_sta+0x33/0x42 [iwl3945]()
> >> >
> >> > Johannes pointed on irc that this problem is most likely caused by:
> >> >
> >> > commit f785d83a19bca326f79d127a413e35769afc0105
> >> > Author: Eliad Peller <eliad@wizery.com>
> >> > Date: Mon Aug 8 16:50:22 2011 +0300
> >> >
> >> > mac80211: clear sta.drv_priv on reconfiguration
> >> >
> >> > Michal, could you confirm that? If that is the root of the problem, we
> >> > need patch for iwlegacy (and iwlwifi) that allocate separate memory for
> >> > rc structures.
> >>
> >> Should I just revert it?
> >
> > Reverted and guess what ;)
> > Yeah, it works. So feel free to add
> > Reported-adn-Tested-by: Michal Hocko <mhocko@suse.cz>
> > to the revert.
> >
> cool. after giving it a second look, i agree with Stanislaw - let's
> continue with the revert.
I'm reverting it now.
> > Anyway, I have really no idea about the 80211 stack but the patch
> > doesn't seem to be correct from the layering POV. Why should generic
> > layer clear something that is driver private data (or at least the
> > naming suggests that it is driver specific data)?
>
> the driver should "know" the station (and its private data) only
> between the .sta_add() and .sta_remove() callbacks.
> on suspend, we do call sta_remove(), so it's valid to clear the private data.
>
> the problem is that the rate control also uses the same private data,
> and is valid also after sta_remove() was called. i think the right
> solution is to split the generic private data and the rate control
> private data.
Sounds like a reasonable plan to me -- thanks for volunteering! :-)
John
--
John W. Linville Someday the world will need a hero, and you
linville@tuxdriver.com might be all we have. Be ready.
next prev parent reply other threads:[~2011-12-01 16:00 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-29 10:07 [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta Michal Hocko
2011-11-29 11:39 ` Stanislaw Gruszka
2011-11-30 10:10 ` Michal Hocko
2011-11-30 14:23 ` Stanislaw Gruszka
2011-11-30 14:03 ` Michal Hocko
2011-11-30 15:39 ` Stanislaw Gruszka
2011-12-01 8:58 ` Michal Hocko
2011-12-01 10:55 ` Michal Hocko
2011-12-01 11:59 ` Stanislaw Gruszka
2011-12-01 12:44 ` Michal Hocko
2011-12-01 12:55 ` Stanislaw Gruszka
2011-12-01 13:13 ` Eliad Peller
2011-12-01 13:31 ` Stanislaw Gruszka
2011-12-01 13:37 ` Sedat Dilek
2011-12-01 14:05 ` Michal Hocko
2011-12-01 14:23 ` Eliad Peller
2011-12-01 15:45 ` John W. Linville [this message]
2011-12-01 12:04 ` Yong Zhang
2011-12-01 12:42 ` Michal Hocko
2011-12-01 2:09 ` Yong Zhang
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