From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: 2.6.21-rc4-mm1: freezing of processes broken Date: Wed, 21 Mar 2007 15:45:16 +0100 Message-ID: <200703211545.17919.rjw@sisk.pl> References: <20070319205623.299d0378.akpm@linux-foundation.org> <1174446834.6665.3.camel@nigel.suspend2.net> <20070321142350.GB78@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20070321142350.GB78@tv-sign.ru> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Oleg Nesterov , Andrew Morton Cc: Sukadev Bhattiprolu , "Eric W. Biederman" , Pavel Machek , linux-pm@lists.osdl.org, linux-kernel@vger.kernel.org, Jiri Slaby List-Id: linux-pm@vger.kernel.org On Wednesday, 21 March 2007 15:23, Oleg Nesterov wrote: > On 03/21, Nigel Cunningham wrote: > > = > > On Tue, 2007-03-20 at 19:23 -0600, Eric W. Biederman wrote: > > > >> > Rafael J. Wysocki napsal(a): > > > > > > > > Bisection shows that the freezing of processes has been broken by o= ne of the > > > > patches: > > > > > > > > remove-the-likelypid-check-in-copy_process.patch > > > = > > > Grr. Oleg's review of remove-the-likelypid-check-in-copy-process > > > showed it to be questionable (and it was just an optimization) > > > so we can get rid of that one easily. = > > > = > > > Although all it did that was really questionable was add > > > the idle process to the global process list and bump a process > > > count when we forked the idle process. Not dramatically dangerous > > > things. > > = > > Could the freezer code be trying to freeze the idle thread as a result? > = > Yes. remove-the-likelypid-check-in-copy_process.patch make idle threads > visible to for_each_process/do_each_thread. Note also that idle threads > have ->mm !=3D NULL. freezer, oom_kill, move_task_off_dead_cpu, etc, shou= ld > not see idle threads, but they do now. Well, I think this is a good enough reason for asking Andrew to drop this patch. Greetings, Rafael