Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:41157 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753963Ab1LANhz convert rfc822-to-8bit (ORCPT ); Thu, 1 Dec 2011 08:37:55 -0500 MIME-Version: 1.0 Reply-To: sedat.dilek@gmail.com In-Reply-To: References: <20111129100727.GD2675@tiehlicka.suse.cz> <20111129113906.GA7299@redhat.com> <20111130101028.GA2906@tiehlicka.suse.cz> <20111130142316.GA2466@redhat.com> <20111130140316.GA4153@tiehlicka.suse.cz> <20111130153929.GA2144@redhat.com> <20111201085845.GA4602@tiehlicka.suse.cz> <20111201105538.GA4504@tiehlicka.suse.cz> <20111201115911.GA5706@redhat.com> <20111201124440.GB25614@tiehlicka.suse.cz> <20111201125554.GC5706@redhat.com> Date: Thu, 1 Dec 2011 14:37:54 +0100 Message-ID: (sfid-20111201_143830_302300_1E9BCB85) Subject: Re: [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta From: Sedat Dilek To: Eliad Peller Cc: Stanislaw Gruszka , Michal Hocko , LKML , "John W. Linville" , linux-wireless@vger.kernel.org, Yong Zhang Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Dec 1, 2011 at 2:13 PM, Eliad Peller wrote: > On Thu, Dec 1, 2011 at 2:55 PM, Stanislaw Gruszka 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 >>> > 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? > Isnt't the mainline handling "user-friendliness first" by reverting "buggy" commits (especially if there is no fix/patch in sight)? A proper fix can be done later. Just my 2 cents. - Sedat - > Eliad. > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html