From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750750AbWJKJWB (ORCPT ); Wed, 11 Oct 2006 05:22:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750763AbWJKJWA (ORCPT ); Wed, 11 Oct 2006 05:22:00 -0400 Received: from mail.suse.de ([195.135.220.2]:26861 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1750750AbWJKJV7 (ORCPT ); Wed, 11 Oct 2006 05:21:59 -0400 Date: Wed, 11 Oct 2006 11:21:58 +0200 From: Nick Piggin To: Andrew Morton Cc: Nick Piggin , Linux Memory Management , Linux Kernel , Linus Torvalds Subject: Re: [patch 2/5] mm: fault vs invalidate/truncate race fix Message-ID: <20061011092158.GA28449@wotan.suse.de> References: <20061010121314.19693.75503.sendpatchset@linux.site> <20061010121332.19693.37204.sendpatchset@linux.site> <20061010213843.4478ddfc.akpm@osdl.org> <452C838A.70806@yahoo.com.au> <20061010230042.3d4e4df1.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061010230042.3d4e4df1.akpm@osdl.org> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 10, 2006 at 11:00:42PM -0700, Andrew Morton wrote: > On Wed, 11 Oct 2006 15:39:22 +1000 > Nick Piggin wrote: > > > But I see that it does read twice. Do you want that behaviour retained? It > > seems like at this level it would be logical to read it once and let lower > > layers take care of any retries? > > argh. Linus has good-sounding reasons for retrying the pagefault-path's > read a single time, but I forget what they are. Something to do with > networked filesystems? (adds cc) While you're there, can anyone tell me why we want an external ptracer to be able to access pages that are outside i_size? I haven't removed the logic of course, but I'm curious about the history and usage of such a thing.