From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934573Ab3BNNJx (ORCPT ); Thu, 14 Feb 2013 08:09:53 -0500 Received: from mail-lb0-f179.google.com ([209.85.217.179]:56287 "EHLO mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757616Ab3BNNJw (ORCPT ); Thu, 14 Feb 2013 08:09:52 -0500 MIME-Version: 1.0 X-Originating-IP: [188.6.195.195] In-Reply-To: <2891124.QXsiBPuYKW@vostro.rjw.lan> References: <1360113112.17267.1.camel@fli24-HP-Compaq-8100-Elite-CMT-PC> <24327774.p6haZy6gvA@vostro.rjw.lan> <2891124.QXsiBPuYKW@vostro.rjw.lan> Date: Thu, 14 Feb 2013 14:09:50 +0100 Message-ID: Subject: Re: Getting rid of freezer for suspend [was Re: [fuse-devel] [PATCH] fuse: make fuse daemon frozen along with kernel threads] From: Miklos Szeredi To: "Rafael J. Wysocki" 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 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 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. 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. Thanks, Miklos