From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [linux-pm] [PATCH 1/4] freezer: make fake_signal_wake_up wake TASK_KILLABLE tasks too Date: Thu, 27 Oct 2011 22:22:39 +0200 Message-ID: <201110272222.39962.rjw@sisk.pl> References: <1317210761-11518-1-git-send-email-jlayton@redhat.com> <20111026155548.4a7c3dd8@corrin.poochiereds.net> <201110272221.06782.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Jeff Layton , linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, trond.myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, john-HpsXz0BELY4AvxtiuMwx3w@public.gmane.org To: linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Return-path: In-Reply-To: <201110272221.06782.rjw-KKrjLPT3xs0@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Thursday, October 27, 2011, Rafael J. Wysocki wrote: > 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). BTW, do you have current versions handy? Or hasn't they changed? Rafael