From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754009AbXGFWtO (ORCPT ); Fri, 6 Jul 2007 18:49:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752045AbXGFWtA (ORCPT ); Fri, 6 Jul 2007 18:49:00 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:60229 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752041AbXGFWtA (ORCPT ); Fri, 6 Jul 2007 18:49:00 -0400 From: "Rafael J. Wysocki" To: Oleg Nesterov Subject: Re: [RFC][PATCH -mm] Freezer: Handle uninterruptible tasks Date: Sat, 7 Jul 2007 00:56:21 +0200 User-Agent: KMail/1.9.5 Cc: Alan Stern , linux-kernel@vger.kernel.org, Nigel Cunningham References: <20070706202629.GA158@tv-sign.ru> In-Reply-To: <20070706202629.GA158@tv-sign.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707070056.22560.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday, 6 July 2007 22:26, Oleg Nesterov wrote: > Rafael J. Wysocki wrote: > > > > This patch makes the freezer skip uninterruptible user space tasks (ie. such > > that have an mm of their own) when counting the tasks to be frozen. As a > > result, these tasks have the TIF_FREEZE and TIF_SIGPENDING flags set, but the > > freezer doesn't wait for them to enter the refrigerator. Nevertheless, they > > will enter the refrigerator as soon as they change their state. > > A small correction: they will enter the refrigerator on return to user-space. Yes, I should have written that explicitly. > Actually, TASK_INTERRUPTIBLE doesn't mean the task actually sleeps. It could > be running or preempted... I am a bit worried :) Fortunately, similar approach has been tested quite extensively by suspend2, IIRC. :-) > > +static int freezer_should_skip(struct task_struct *p) > > +{ > > + return (has_mm(p) && (p->state | TASK_UNINTERRUPTIBLE)); > ^^^ > I guess you meant "&", not "|". Yes, I've already spotted that, but thanks anyway. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth