From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932069AbWAJGYe (ORCPT ); Tue, 10 Jan 2006 01:24:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932074AbWAJGYd (ORCPT ); Tue, 10 Jan 2006 01:24:33 -0500 Received: from 217-133-42-200.b2b.tiscali.it ([217.133.42.200]:1109 "EHLO opteron.random") by vger.kernel.org with ESMTP id S932069AbWAJGYd (ORCPT ); Tue, 10 Jan 2006 01:24:33 -0500 Date: Tue, 10 Jan 2006 07:24:25 +0100 From: Andrea Arcangeli To: Andrew Morton Cc: linux-kernel@vger.kernel.org, hugh@veritas.com Subject: Re: smp race fix between invalidate_inode_pages* and do_no_page Message-ID: <20060110062425.GA15897@opteron.random> References: <20051213193735.GE3092@opteron.random> <20051213130227.2efac51e.akpm@osdl.org> <20051213211441.GH3092@opteron.random> <20051216135147.GV5270@opteron.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051216135147.GV5270@opteron.random> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 16, 2005 at 02:51:47PM +0100, Andrea Arcangeli wrote: > There was a minor buglet in the previous patch an update is here: > > http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.15-rc5/seqschedlock-2 JFYI: I got a few hours ago positive confirmation of the fix from the customer that was capable of reproducing this. I guess this is good enough for production use (it's at the very least certainly better than the previous code and it's guaranteed not to hurt the scalability of the fast path in smp, so it's the least intrusive fix I could imagine). So we can start to think if we should using this new primitive I created, and if to replace the yield() with a proper waitqueue (and how). Or if to take the risk of hitting a bit of scalability in the nopage page faults of processes, by rewriting the fix with a find_lock_page in the do_no_page handler, that would avoid the need of my new locking primitive. Comments welcome thanks!