From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from ogre.sisk.pl ([217.79.144.158]:36351 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752202Ab1J0USe (ORCPT ); Thu, 27 Oct 2011 16:18:34 -0400 From: "Rafael J. Wysocki" To: Jeff Layton Subject: Re: [PATCH 1/4] freezer: make fake_signal_wake_up wake TASK_KILLABLE tasks too Date: Thu, 27 Oct 2011 22:21:06 +0200 Cc: Pavel Machek , trond.myklebust@netapp.com, smfrench@gmail.com, linux-pm@lists.linux-foundation.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, john@calva.com, linux-kernel@vger.kernel.org References: <1317210761-11518-1-git-send-email-jlayton@redhat.com> <201110112114.28478.rjw@sisk.pl> <20111026155548.4a7c3dd8@corrin.poochiereds.net> In-Reply-To: <20111026155548.4a7c3dd8@corrin.poochiereds.net> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201110272221.06782.rjw@sisk.pl> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wednesday, October 26, 2011, Jeff Layton wrote: > On Tue, 11 Oct 2011 21:14:28 +0200 > "Rafael J. Wysocki" wrote: > > > On Tuesday, October 11, 2011, Jeff Layton wrote: > > > On Tue, 11 Oct 2011 08:18:48 +0200 > > > Pavel Machek wrote: > > > > > > > > > > > Hi! > > > > > > > > > TASK_KILLABLE is often used to put tasks to sleep for quite some time. > > > > > One of the most common uses is to put tasks to sleep while waiting for > > > > > replies from a server on a networked filesystem (such as CIFS or NFS). > > > > > > > > > > Unfortunately, fake_signal_wake_up does not currently wake up tasks > > > > > that are sleeping in TASK_KILLABLE state. This means that even if the > > > > > code were in place to allow them to freeze while in this sleep, it > > > > > wouldn't work anyway. > > > > > > > > > > This patch changes this function to wake tasks in this state as well. > > > > > This should be harmless -- if the code doing the sleeping doesn't have > > > > > handling to deal with freezer events, it should just go back to sleep. > > > > > > > > I'm pretty sure this will break something; but that does not mean it > > > > is bad idea, just that it should be merged early and tested a lot. > > > > > > > > > > FWIW, I looked at most of the places in the kernel that do > > > TASK_KILLABLE sleeps and they look like they'll handle this correctly. > > > The main one I wasn't sure about was mem_cgroup_handle_oom(), but I > > > think it'll do the right thing too. I certainly could have missed > > > something though... > > > > > > In any case, would you mind merging this via the linux-pm tree for 3.2? > > > > I will push it for 3.2. > > > > Hi Rafael, > > Trond asked if you would also be willing to push patches 3 and 4 in > this series for 3.2 as well [1]? Note that patch #4 got another revision so > we'll want to make sure that you get that one. I can resend the > nfs/sunrpc patches if that will help... > > [1]: I think Steve F is going to push patch #2, so that one shouldn't > be an issue. Well, I've already sent my pull request. I can keep these patches in my tree for the next pull request, though (I'm sure there will be fixes against 3.2, so they will go along with those). Thanks, Rafael