Re: [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta

From: Eliad Peller
Date: Thu Dec 01 2011 - 08:13:44 EST


On Thu, Dec 1, 2011 at 2:55 PM, Stanislaw Gruszka <sgruszka@xxxxxxxxxx> wrote:
> On Thu, Dec 01, 2011 at 01:44:40PM +0100, 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@xxxxxxxxxx>
>> > 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.
> Actually this require quite big changes in iwlegacy at least, perhaps
> also in iwlwifi. I prefer to revert commit as temporary fix,  and add
> memset(0) to drivers .add_sta callback, in drivers which need it. After
> changing iwlegcy/iwlwifi we could move memset(0) back to ieee80211_reconfig().
>
> Eliad, thoughts?
>
i don't really care about temporarily reverting it.
but maybe you can just add an "initialized" flag to iwl3945_rs_sta,
and check it on free_sta?

Eliad.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/