Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755736AbYFWSh1 (ORCPT ); Mon, 23 Jun 2008 14:37:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755706AbYFWShQ (ORCPT ); Mon, 23 Jun 2008 14:37:16 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:34816 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755137AbYFWShP (ORCPT ); Mon, 23 Jun 2008 14:37:15 -0400 Date: Mon, 23 Jun 2008 11:32:54 -0700 (PDT) From: Linus Torvalds To: Jeff Chua cc: Hugh Dickins , Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Oleg Nesterov , Nick Piggin , KAMEZAWA Hiroyuki , Ingo Molnar , Roland McGrath Subject: Re: [patch 2/5] Reinstate ZERO_PAGE optimization in get_user_pages() and fix XIP In-Reply-To: Message-ID: References: <20080622185327.348377223@mini.kroah.org> <20080622190140.GD20141@suse.de> <20080622202950.GB20800@suse.de> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) 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: 1209 Lines: 32 On Tue, 24 Jun 2008, Jeff Chua wrote: > On Tue, Jun 24, 2008 at 1:27 AM, Linus Torvalds > wrote: > > > On the other hand, if you add a trace to the "use_zero_page()" function to > > print out the vm_flags and other details, that probably would help. > > Let me know if you still want me to test this. No, it's fine. It really was a bug, and a long-standing one, just one that was probably practically impossible to hit before (because we used to only do the FOLL_ANON logic on missing whole page tables, and just about any access to any mapping even nearby the one you care about will fill in the page tables - so you would have had to be really unlucky to trigger the case before). The patch clearly fixes an issue, and makes the code more readable and maintainable too, so I don't care what the exact mapping flags etc were. > Yeh, it works great! Thank you. Thanks for bisecting, reporting and testing. 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/