From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754138AbXGFWwq (ORCPT ); Fri, 6 Jul 2007 18:52:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751670AbXGFWwj (ORCPT ); Fri, 6 Jul 2007 18:52:39 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:60255 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751415AbXGFWwi convert rfc822-to-8bit (ORCPT ); Fri, 6 Jul 2007 18:52:38 -0400 From: "Rafael J. Wysocki" To: Oliver Neukum Subject: Re: [RFC][PATCH -mm] Freezer: Handle uninterruptible tasks Date: Sat, 7 Jul 2007 01:00:16 +0200 User-Agent: KMail/1.9.5 Cc: Oleg Nesterov , Alan Stern , linux-kernel@vger.kernel.org References: <20070706202629.GA158@tv-sign.ru> <200707070038.25830.oliver@neukum.org> In-Reply-To: <200707070038.25830.oliver@neukum.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200707070100.17413.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday, 7 July 2007 00:38, Oliver Neukum wrote: > Am Freitag, 6. Juli 2007 schrieb Oleg Nesterov: > > 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. > > That is too late. We would need them to go to sleep as soon as they are > woken up. This does not matter if they are in uninterruptible sleep due to > fuse deadlocking, as they won't be woken up, but it kills the other cases. I'm sorry I can't write anything more about that right now, I'll write more tomorrow. For now, I can only say that I have reasons to believe that the other cases are not likely to "leak" through the freezer. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth