From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: windfarm got signal Date: Thu, 22 Jun 2006 13:03:19 +0200 Message-ID: <200606221303.19860.rjw@sisk.pl> References: <1150847482.16662.13.camel@johannes> <1150956123.3633.23.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1150956123.3633.23.camel@localhost.localdomain> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Benjamin Herrenschmidt Cc: linuxppc-dev list , Johannes Berg , linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Thursday 22 June 2006 08:02, Benjamin Herrenschmidt wrote: > On Wed, 2006-06-21 at 01:51 +0200, Johannes Berg wrote: > > Hey, > > = > > after cpu hotplug I decided to write some fake suspend routines for > > ppc64 that always fail to see what all the drivers would say... The > > first thing I saw was during the phase where all threads are stopped, > > that windfarm got a signal! > > = > > Shortly after that, the fans were revved up fully but I guess that's > > expected if the wf control loop exits. > > = > > So now I'm trying to see *why* it got a signal there. Any ideas? Is that > > expected with pm and windfarm just does the wrong thing there by taking > > the signal as a reason to exit the control thread? > > = > > [code in question is windfarm_core.c:wf_thread_func] > = > I think it's the way the freezer works ... it sends a pseudo signal to > all kernel threads who are then supposed to do something like test for > PF_FREEZE or something like that. Yes. More precisely, they are supposed to use try_to_freeze(). Please see Documentation/power/kernel_threads.txt. Greetings, Rafael