From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934791Ab3BNRbr (ORCPT ); Thu, 14 Feb 2013 12:31:47 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:38157 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932434Ab3BNRbd (ORCPT ); Thu, 14 Feb 2013 12:31:33 -0500 From: "Rafael J. Wysocki" To: Miklos Szeredi Cc: Pavel Machek , Goswin von Brederlow , Li Fei , len.brown@intel.com, mingo@redhat.com, peterz@infradead.org, biao.wang@intel.com, linux-pm@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chuansheng.liu@intel.com Subject: Re: Getting rid of freezer for suspend [was Re: [fuse-devel] [PATCH] fuse: make fuse daemon frozen along with kernel threads] Date: Thu, 14 Feb 2013 18:38:02 +0100 Message-ID: <6332427.iqPUMjtDaQ@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc7; KDE/4.9.5; x86_64; ; ) In-Reply-To: References: <1360113112.17267.1.camel@fli24-HP-Compaq-8100-Elite-CMT-PC> <2891124.QXsiBPuYKW@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, February 14, 2013 02:09:50 PM Miklos Szeredi wrote: > On Thu, Feb 14, 2013 at 1:11 PM, Rafael J. Wysocki wrote: > > On Thursday, February 14, 2013 11:41:16 AM Miklos Szeredi wrote: > > >> > >> It is essentially the same mechanism that is used to delay the > >> freezing of kernel threads after userspace tasks have been frozen. > >> Except it's a lot more difficult to determine which userspace tasks > >> need to be suspended late and which aren't. > > > > Well, I suppose that information is available to user space. > > > > Do we need an interface for a process to mark itself as PF_FREEZE_LATE or > > do we need an interface for one process to mark another process as > > PF_FREEZE_LATE, or both? > > As a first step marking self with PF_FREEZE_LATE and inheriting this > flag across fork/clone would work for most cases, I think. OK, so we can just have a switch for that in /proc I suppose. > Marking an unrelated process would have all sorts of issues: Who has > permission to do this? Won't it be misused to "fix" random freezer > issues. Yes, that's why I was asking. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.