Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762350AbZDHP5M (ORCPT ); Wed, 8 Apr 2009 11:57:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760855AbZDHP4y (ORCPT ); Wed, 8 Apr 2009 11:56:54 -0400 Received: from mail.pikewerks.com ([24.96.136.236]:52405 "EHLO mail.pikewerks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758777AbZDHP4x (ORCPT ); Wed, 8 Apr 2009 11:56:53 -0400 Message-ID: <49DCC936.70509@pikewerks.com> Date: Wed, 08 Apr 2009 08:56:38 -0700 From: Matt Klein User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) MIME-Version: 1.0 To: Peter Zijlstra CC: linux-kernel@vger.kernel.org, Nick Piggin Subject: Re: Cached IO Synchronization Question References: <49DA7498.3050000@pikewerks.com> <1239204217.4557.2590.camel@laptop> In-Reply-To: <1239204217.4557.2590.camel@laptop> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 661 Lines: 18 > > Note how do_generic_file_read() checks PageUptodate() and does a > lock_page_killable() in case its not. > > > As far as I can tell there is nothing to prevent the page from becoming out of date (or someone doing a full page cached write) after the PageUptodate() check returns up to date. So I have concluded that cached read/write interleaving is not synchronized. This is the behavior found on Windows. -- 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/