From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: question on resume() Date: Wed, 31 Jan 2007 09:49:03 +0100 Message-ID: <200701310949.04110.rjw@sisk.pl> References: <200701291206.39637.oneukum@suse.de> <200701310933.29443.rjw@sisk.pl> <200701310940.26040.oliver@neukum.name> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200701310940.26040.oliver@neukum.name> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Oliver Neukum Cc: linux-kernel@vger.kernel.org, nigel@nigel.suspend2.net, pm list List-Id: linux-pm@vger.kernel.org On Wednesday, 31 January 2007 09:40, Oliver Neukum wrote: > Am Mittwoch, 31. Januar 2007 09:33 schrieb Rafael J. Wysocki: > > On Tuesday, 30 January 2007 23:32, Rafael J. Wysocki wrote: > > > > Generally, you are safe if your driver only calls wake_up() from a process > > > context, but not from .resume() or .suspend() routines (or from an > > > unfreezeable kernel thread). > > > > Ah, sorry, I've just realized I was wrong. Processes in TASK_UNINTERRUPTIBLE > > cannot be frozen! So, the above only applies to wake_up_interruptible(). > > So the kernel will wait for tasks in TASK_UNINTERRUPTIBLE to finish IO > before it calls suspend()? I am confused. Yes, it will. The process freezer can only return success if there are no more TASK_UNINTERRUPTIBLE tasks. Otherwise it fails (after a timeout). Greetings, Rafael -- If you don't have the time to read, you don't have the time or the tools to write. - Stephen King