From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pallipadi, Venkatesh" Subject: Re: [Bug #13424] possible deadlock when doing governor switching Date: Mon, 29 Jun 2009 11:37:45 -0700 Message-ID: <1246300665.4534.26170.camel@localhost.localdomain> References: <5Hhc7UkUKEO.A.IOG.9jASKB@chimera> <20090629012558.GA22666@Krystal> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090629012558.GA22666@Krystal> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Mathieu Desnoyers Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , "Li, Shaohua" , davej-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org On Sun, 2009-06-28 at 18:25 -0700, Mathieu Desnoyers wrote: > * Rafael J. Wysocki (rjw-KKrjLPT3xs0@public.gmane.org) wrote: > > This message has been generated automatically as a part of a report > > of regressions introduced between 2.6.29 and 2.6.30. > > > > The following bug entry is on the current list of known regressions > > introduced between 2.6.29 and 2.6.30. Please verify if it still should > > be listed and let me know (either way). > > > > Yep, it still exists. Venkatesh Pallipadi from Intel is working on it. > We need to figure out a proper way to fix policy rwlock vs dbs_mutex vs > timer mutex dependency. > Yes. Still working on it. I thought I had a fix for this. But, over the weekend test run resulted in a WARN_ON with sysfs_remove_group as below. Looks like I need a day or two more to work through the web of locks here.. Thanks, Venki [10412.466195] ------------[ cut here ]------------ [10412.466201] WARNING: at /home/venkip/src/linus/linux-2.6/fs/sysfs/group.c:138 sysfs_remove_group+0x3e/0xa3() [10412.466204] Hardware name: Santa Rosa platform [10412.466206] sysfs group c16df3b0 not found for kobject 'cpufreq' [10412.466207] Modules linked in: [10412.466210] Pid: 20609, comm: write_syscpufre Not tainted 2.6.31-rc1 #195 [10412.466212] Call Trace: [10412.466217] [] warn_slowpath_common+0x60/0x90 [10412.466220] [] warn_slowpath_fmt+0x24/0x27 [10412.466223] [] sysfs_remove_group+0x3e/0xa3 [10412.466227] [] cpufreq_governor_dbs+0x1f7/0x25b [10412.466231] [] __cpufreq_governor+0x7c/0xb3 [10412.466234] [] __cpufreq_set_policy+0x13f/0x1c3 [10412.466238] [] store_scaling_governor+0x18a/0x1b2 [10412.466241] [] ? handle_update+0x0/0x28 [10412.466244] [] ? lock_policy_rwsem_write+0x33/0x5b [10412.466247] [] ? store_scaling_governor+0x0/0x1b2 [10412.466250] [] store+0x48/0x61 [10412.466254] [] sysfs_write_file+0xb4/0xdf [10412.466265] [] ? sysfs_write_file+0x0/0xdf [10412.466269] [] vfs_write+0x84/0xdf [10412.466272] [] sys_write+0x3b/0x60 [10412.466276] [] sysenter_do_call+0x12/0x22 [10412.466278] ---[ end trace 31a730d96cbc1841 ]---