From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 3 Oct 2017 22:51:50 +0200 (CEST) From: Jiri Kosina To: Bart Van Assche cc: "pavel@ucw.cz" , "darrick.wong@oracle.com" , "viro@zeniv.linux.org.uk" , "ming.lei@redhat.com" , "rjw@rjwysocki.net" , "mcgrof@kernel.org" , "linux-fsdevel@vger.kernel.org" , "len.brown@intel.com" , "tytso@mit.edu" , "boris.ostrovsky@oracle.com" , "ONeukum@suse.com" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nborisov@suse.com" , "oleg.b.antonyan@gmail.com" , "linux-pm@vger.kernel.org" , "linux-xfs@vger.kernel.org" , "jgross@suse.com" , "martin.petersen@oracle.com" , "oleksandr@natalenko.name" , "todd.e.brandt@linux.intel.com" , "jack@suse.cz" Subject: Re: [RFC 5/5] pm: remove kernel thread freezing In-Reply-To: Message-ID: References: <20171003185313.1017-1-mcgrof@kernel.org> <20171003185313.1017-6-mcgrof@kernel.org> <1507061605.2567.13.camel@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, 3 Oct 2017, Jiri Kosina wrote: > > What about the many drivers outside filesystems that use the > > set_freezable() / try_to_freeze() / wait_event_freezable() API? > > Many/most of them are just completely bogus and pointless. More specifically -- they don't really care at all whether they get scheduled out exactly at the try_to_freeze() point; they are perfectly happy being scheduled out at any other scheduling point, and land on runqueue after the resume has been completed. Sure, certain drivers need to take action when system is undergoing hibernation/suspend. But that's what PM callbacks are for, not kthread hibernation. -- Jiri Kosina SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Kosina Subject: Re: [RFC 5/5] pm: remove kernel thread freezing Date: Tue, 3 Oct 2017 22:51:50 +0200 (CEST) Message-ID: References: <20171003185313.1017-1-mcgrof@kernel.org> <20171003185313.1017-6-mcgrof@kernel.org> <1507061605.2567.13.camel@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: Received: from mx2.suse.de ([195.135.220.15]:46289 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750841AbdJCUvx (ORCPT ); Tue, 3 Oct 2017 16:51:53 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Bart Van Assche Cc: "pavel@ucw.cz" , "darrick.wong@oracle.com" , "viro@zeniv.linux.org.uk" , "ming.lei@redhat.com" , "rjw@rjwysocki.net" , "mcgrof@kernel.org" , "linux-fsdevel@vger.kernel.org" , "len.brown@intel.com" , "tytso@mit.edu" , "boris.ostrovsky@oracle.com" , "ONeukum@suse.com" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nborisov@suse.com" , "oleg.b.antonyan@gmail.com" , "linux-pm@vger.kernel.org" On Tue, 3 Oct 2017, Jiri Kosina wrote: > > What about the many drivers outside filesystems that use the > > set_freezable() / try_to_freeze() / wait_event_freezable() API? > > Many/most of them are just completely bogus and pointless. More specifically -- they don't really care at all whether they get scheduled out exactly at the try_to_freeze() point; they are perfectly happy being scheduled out at any other scheduling point, and land on runqueue after the resume has been completed. Sure, certain drivers need to take action when system is undergoing hibernation/suspend. But that's what PM callbacks are for, not kthread hibernation. -- Jiri Kosina SUSE Labs