From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261431AbVFBVwD (ORCPT ); Thu, 2 Jun 2005 17:52:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261346AbVFBVuk (ORCPT ); Thu, 2 Jun 2005 17:50:40 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:5251 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S261231AbVFBVrj (ORCPT ); Thu, 2 Jun 2005 17:47:39 -0400 Date: Thu, 2 Jun 2005 23:47:14 +0200 From: Pavel Machek To: Nigel Cunningham Cc: Benjamin Herrenschmidt , Linux Kernel Mailing List Subject: Re: Freezer Patches. Message-ID: <20050602214714.GB1980@elf.ucw.cz> References: <1117663709.13830.34.camel@localhost> <20050601223101.GD11163@elf.ucw.cz> <1117665934.19020.94.camel@gaston> <20050601230235.GF11163@elf.ucw.cz> <1117676753.10888.105.camel@localhost> <20050602071431.GA1841@elf.ucw.cz> <1117697187.10888.138.camel@localhost> <20050602073119.GC1841@elf.ucw.cz> <1117697772.31082.54.camel@gaston> <1117700339.10888.141.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1117700339.10888.141.camel@localhost> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > Whatever you guys decide to do (I actually do sys_sync() before freezing > > on pmac and yes, it takes sometimes way too long), to be uber-safe, we > > could/should _also_ do sync after freezing userland processes and before > > freezing kernel threads (that is, splitting here). In fact, that would > > help also avoid deadlocks where a frozen kernel thread is holding a > > semaphore preventing a process from freezing. > > > > That way, if we sys_sync() once processes are sleeping and before kernel > > threads are, we pretty-much make sure no new dirty buffer will appear. > > > > Anyway, that's mostly food for thoughts at this point > > I fully agree, and that's what I'm already doing. Nothing I can do about > Pavel not seeing logic, so guess I just have to hope everyone else does > :) I think I see your logic, and it is wrong. Anyway, just do not touch fork/exit hot paths. Pavel