Return-path: Received: from mail-iy0-f174.google.com ([209.85.210.174]:37472 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753691Ab1LAMEL (ORCPT ); Thu, 1 Dec 2011 07:04:11 -0500 Date: Thu, 1 Dec 2011 20:04:01 +0800 From: Yong Zhang To: Michal Hocko Cc: Stanislaw Gruszka , LKML , "John W. Linville" , linux-wireless@vger.kernel.org Subject: Re: [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta Message-ID: <20111201120400.GA2112@zhy> (sfid-20111201_130428_538156_80D99A9B) Reply-To: Yong Zhang 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <20111201105538.GA4504@tiehlicka.suse.cz> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Dec 01, 2011 at 11:55:38AM +0100, Michal Hocko wrote: > On Thu 01-12-11 09:58:45, Michal Hocko wrote: > [...] > > I will try to turn on timer debugging suggested by Yong Zhang in other > > email. > > OK, so applied the following commits: > $ git shortlog master.. > Christine Chan (2): > timer: Use debugobjects to catch deletion of uninitialized timers > debugobjects: Extend to assert that an object is initialized > > Michal Hocko (1): > Debugging patch > > Stephen Boyd (2): > timer: Setup uninitialized timer with a stub callback > debugobjects: Be smarter about static objects > > Debugging patch is the one from Stanislaw posted earlier in the thread. > It prevents del_timer_sync and warns on NULL timer in iwl3945_rs_free_sta. > Also turned on the suggested DEBUG_OBJECTS_TIMERS. > > I do not see any timer related warnings. I will try it with the slightly > modified Debugging patch and just warn without returning before calling > del_timer_sync. > > [ 349.316076] ------------[ cut here ]------------ > [ 349.316097] WARNING: at drivers/net/wireless/iwlegacy/iwl-3945-rs.c:438 iwl3945_rs_free_sta+0x33/0x42 [iwl3945]() > [ 349.316105] Hardware name: LIFEBOOK S7110 > [ 349.316110] Modules linked in: aes_i586 aes_generic i915 fbcon font bitblit softcursor drm_kms_helper drm fb fbdev i2c_algo_bit cfbcopyarea i2c_core cfbimgblt cfbfillrect fuse tun coretemp hwmon snd_hda_codec_realtek arc4 snd_hda_intel snd_hda_codec snd_pcm_oss snd_mixer_oss iwl3945 snd_pcm iwl_legacy snd_seq_oss snd_seq_midi_event mac80211 snd_seq snd_timer snd_seq_device cfg80211 snd video snd_page_alloc fujitsu_laptop backlight [last unloaded: scsi_wait_scan] > [ 349.316203] Pid: 12, comm: kworker/u:1 Tainted: G W 3.2.0-rc3-timerstest-00009-g762dd0e #20 ^ seems there was warning but we did't catch it, right? not sure if it's related. Thanks, Yong > [ 349.316209] Call Trace: > [ 349.316223] [] warn_slowpath_common+0x68/0x7d > [ 349.316237] [] ? iwl3945_rs_free_sta+0x33/0x42 [iwl3945] > [ 349.316247] [] warn_slowpath_null+0x14/0x18 > [ 349.316260] [] iwl3945_rs_free_sta+0x33/0x42 [iwl3945] > [ 349.316283] [] __sta_info_free.isra.24+0x28/0x60 [mac80211] > [ 349.316304] [] __sta_info_destroy+0x259/0x283 [mac80211] > [ 349.316328] [] sta_info_flush+0x43/0x6e [mac80211] > [ 349.316353] [] ieee80211_set_disassoc+0x1a3/0x1d7 [mac80211] > [ 349.316379] [] ieee80211_sta_connection_lost+0x31/0x8a [mac80211] > [ 349.316390] [] ? dev_printk+0x2b/0x2d > [ 349.316416] [] ieee80211_sta_work+0x1b0/0x1c3 [mac80211] > [ 349.316446] [] ieee80211_iface_work+0x23e/0x250 [mac80211] > [ 349.316457] [] process_one_work+0x19b/0x2e6 > [ 349.316483] [] ? ieee80211_netdev_select_queue+0x14/0x14 [mac80211] > [ 349.316492] [] worker_thread+0x136/0x1ee > [ 349.316501] [] ? manage_workers.isra.23+0x14f/0x14f > [ 349.316509] [] kthread+0x67/0x6c > [ 349.316517] [] ? kthread_worker_fn+0x119/0x119 > [ 349.316527] [] kernel_thread_helper+0x6/0x10 > [ 349.316532] ---[ end trace 5cf96275a244e7ca ]--- > [ 349.316538] ieee80211 phy0: Destroyed STA 00:0b:6b:3c:8c:e4 > [ 349.316556] ieee80211 phy0: device now idle > [ 349.328105] cfg80211: Calling CRDA to update world regulatory domain > [ 349.416952] ieee80211 phy0: device no longer idle - scanning > [ 353.091211] ieee80211 phy0: device now idle > [ 358.092230] ieee80211 phy0: device no longer idle - scanning > [ 361.772470] ieee80211 phy0: device now idle > [ 366.774826] ieee80211 phy0: device no longer idle - scanning > [ 370.448401] ieee80211 phy0: device now idle > [ 375.455127] ieee80211 phy0: device no longer idle - scanning > [ 379.127638] ieee80211 phy0: device now idle > [ 384.131847] ieee80211 phy0: device no longer idle - scanning > [ 387.806711] ieee80211 phy0: device now idle > [ 396.708125] sky2 0000:02:00.0: lan0: Link is up at 1000 Mbps, full duplex, flow control both > [ 407.120063] lan0: no IPv6 routers present > [ 434.003896] ieee80211 phy0: device no longer idle - scanning > [ 438.694843] ieee80211 phy0: device now idle > [ 441.485602] process `skype' is using obsolete setsockopt SO_BSDCOMPAT > [ 494.004619] ieee80211 phy0: device no longer idle - scanning > [ 498.698796] ieee80211 phy0: device now idle > [ 554.004822] ieee80211 phy0: device no longer idle - scanning > [ 558.697908] ieee80211 phy0: device now idle > [ 614.003956] ieee80211 phy0: device no longer idle - scanning > [ 618.700408] ieee80211 phy0: device now idle > [ 674.004164] ieee80211 phy0: device no longer idle - scanning > [ 678.702423] ieee80211 phy0: device now idle > > -- > Michal Hocko > SUSE Labs > SUSE LINUX s.r.o. > Lihovarska 1060/12 > 190 00 Praha 9 > Czech Republic