From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753922Ab2A3WXQ (ORCPT ); Mon, 30 Jan 2012 17:23:16 -0500 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:46028 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752232Ab2A3WXP (ORCPT ); Mon, 30 Jan 2012 17:23:15 -0500 Message-ID: <4F271849.302@linux.vnet.ibm.com> Date: Tue, 31 Jan 2012 03:53:05 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux i686; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: Tejun Heo CC: rjw@sisk.pl, pavel@ucw.cz, len.brown@intel.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] PM/Freezer: Make thaw_processes() thaw only userspace tasks References: <20120130220259.9442.70091.stgit@srivatsabhat.in.ibm.com> <20120130220419.9442.39596.stgit@srivatsabhat.in.ibm.com> <20120130220919.GC27616@google.com> In-Reply-To: <20120130220919.GC27616@google.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12013022-2674-0000-0000-0000032BB974 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/31/2012 03:39 AM, Tejun Heo wrote: > On Tue, Jan 31, 2012 at 03:34:57AM +0530, Srivatsa S. Bhat wrote: >> Currently the situation is: >> >> freeze_processes() - freezes only userspace tasks >> freeze_kernel_threads() - freezes only kernel threads >> thaw_kernel_threads() - thaws only kernel threads >> thaw_processes() - thaws *everything* (both userspace tasks and kernel threads) >> >> The point that thaw_processes() thaws everything is rather unintuitive >> and can lead to bugs. So, modify thaw_processes() so that it thaws only >> userspace processes. This way we can also have more control over what >> exactly gets thawed in different situations. >> >> Signed-off-by: Srivatsa S. Bhat > > Maybe I'm misreading it but doesn't this introduce window where kernel > tasks aren't thawed between this patch and the following ones? It > looks like this one should come later. > Yes, I was aware that it introduces such a window. But I ignored it in the interest of making the patch series sensible (as in, for example, patch 2/4 wouldn't make much sense without patch 1/4). Maybe I will interchange patch 1 and patch 2 and just reword the patch descriptions suitably so that they still make sense.. Thanks a lot! Regards, Srivatsa S. Bhat