From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail01.adl2.internode.on.net ([150.101.137.133]:3519 "EHLO ipmail01.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751156AbdJDHSJ (ORCPT ); Wed, 4 Oct 2017 03:18:09 -0400 Date: Wed, 4 Oct 2017 18:18:03 +1100 From: Dave Chinner Subject: Re: [RFC 5/5] pm: remove kernel thread freezing Message-ID: <20171004071803.GF3666@dastard> References: <20171003185313.1017-1-mcgrof@kernel.org> <20171003185313.1017-6-mcgrof@kernel.org> <1862632.MOTT9GD8nq@aspire.rjw.lan> <29004244.0jnB6Wc1z6@aspire.rjw.lan> <20171004004756.GN2294@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171004004756.GN2294@wotan.suse.de> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Luis R. Rodriguez" Cc: "Rafael J. Wysocki" , viro@zeniv.linux.org.uk, bart.vanassche@wdc.com, ming.lei@redhat.com, tytso@mit.edu, darrick.wong@oracle.com, jikos@kernel.org, pavel@ucw.cz, len.brown@intel.com, linux-fsdevel@vger.kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com, todd.e.brandt@linux.intel.com, nborisov@suse.com, jack@suse.cz, martin.petersen@oracle.com, ONeukum@suse.com, oleksandr@natalenko.name, oleg.b.antonyan@gmail.com, linux-pm@vger.kernel.org, linux-block@vger.kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org On Wed, Oct 04, 2017 at 02:47:56AM +0200, Luis R. Rodriguez wrote: > On Tue, Oct 03, 2017 at 11:15:07PM +0200, Rafael J. Wysocki wrote: > > On Tuesday, October 3, 2017 8:59:00 PM CEST Rafael J. Wysocki wrote: > > > On Tuesday, October 3, 2017 8:53:13 PM CEST Luis R. Rodriguez wrote: > > > > Now that all filesystems which used to rely on kthread > > > > freezing have been converted to filesystem freeze/thawing > > > > we can remove the kernel kthread freezer. > > > > > > > > Signed-off-by: Luis R. Rodriguez > > > > > > I like this one. :-) > > > > However, suspend_freeze/thaw_processes() require some more work. > > > > In particular, the freezing of workqueues is being removed here > > without a replacement. > > Hrm, where do you see that? freeze_workqueues_busy() is still called on > try_to_freeze_tasks(). Likewise thaw_processes() also calls thaw_workqueues(). > I did forget to nuke pm_nosig_freezing though. static int try_to_freeze_tasks(bool user_only) { ..... if (!user_only) freeze_workqueues_begin(); ..... if (!user_only) { wq_busy = freeze_workqueues_busy(); ..... } i.e. only try_to_freeze_tasks(false) will freeze workqueues, and the only function that calls that - freeze_kernel_threads() - is removed by this patch. Cheers, Dave. -- Dave Chinner david@fromorbit.com