Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751944Ab0AGUJT (ORCPT ); Thu, 7 Jan 2010 15:09:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751185Ab0AGUJS (ORCPT ); Thu, 7 Jan 2010 15:09:18 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:38017 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783Ab0AGUJS (ORCPT ); Thu, 7 Jan 2010 15:09:18 -0500 Date: Thu, 7 Jan 2010 12:08:25 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Christoph Lameter cc: Peter Zijlstra , Arjan van de Ven , "Paul E. McKenney" , KAMEZAWA Hiroyuki , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" , "hugh.dickins" , Nick Piggin , Ingo Molnar Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault() In-Reply-To: Message-ID: References: <20100104182429.833180340@chello.nl> <20100104182813.753545361@chello.nl> <20100105054536.44bf8002@infradead.org> <20100105192243.1d6b2213@infradead.org> <1262884960.4049.106.camel@laptop> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 865 Lines: 25 On Thu, 7 Jan 2010, Christoph Lameter wrote: > > page_table_lock used to serialize multiple fast brks? > > CONFIG_SPLIT_PTLOCK implies that code will not use this lock in fault > handling. So no serialization with faults. Correct. The faults we do not need to serialize with. It doesn't matter whether they see the old or the new end. > Also the current code assumes vm_end and so on to be stable if mmap_sem is > held. F.e. find_vma() from do_fault is now running while vm_end may be changing > under it. Again, it doesn't matter. Old or new - if some other thread looks up the vma, either is fine. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/