From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751412AbWIONa5 (ORCPT ); Fri, 15 Sep 2006 09:30:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751420AbWIONa5 (ORCPT ); Fri, 15 Sep 2006 09:30:57 -0400 Received: from excu-mxob-1.symantec.com ([198.6.49.12]:40599 "EHLO excu-mxob-1.symantec.com") by vger.kernel.org with ESMTP id S1751412AbWIONa5 (ORCPT ); Fri, 15 Sep 2006 09:30:57 -0400 Date: Fri, 15 Sep 2006 14:30:24 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Andrew Morton cc: Benjamin Herrenschmidt , linux-mm@kvack.org, Linux Kernel list , Linus Torvalds , Mike Waychison Subject: Re: [RFC] page fault retry with NOPAGE_RETRY In-Reply-To: <20060915003529.8a59c542.akpm@osdl.org> Message-ID: References: <1158274508.14473.88.camel@localhost.localdomain> <20060915001151.75f9a71b.akpm@osdl.org> <20060915003529.8a59c542.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 15 Sep 2006 13:30:21.0740 (UTC) FILETIME=[17E3BEC0:01C6D8CB] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 15 Sep 2006, Andrew Morton wrote: > > This assumes that no other heavyweight process will try to modify this > single-threaded process's mm. I don't _think_ that happens anywhere, does > it? access_process_vm() is the only case I can think of, "Modify" in the sense of fault into. Yes, access_process_vm() is all I can think of too. > and it does down_read(other process's mmap_sem). If there were anything else, it'd have to do so too (if not down_write). I too like NOPAGE_RETRY: as you've both observed, it can help to solve several different problems. Hugh