Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937471AbWLEHiS (ORCPT ); Tue, 5 Dec 2006 02:38:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S937472AbWLEHiR (ORCPT ); Tue, 5 Dec 2006 02:38:17 -0500 Received: from ug-out-1314.google.com ([66.249.92.174]:16783 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937471AbWLEHiR (ORCPT ); Tue, 5 Dec 2006 02:38:17 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=K78/7OmpsAxQQagVes1gMy9RABqCK755AyCdRAa2kk4z0KG3kfFPcOv3EYsgVNkqGq/+x+j28U8CH2hhl+PNGJfalzdFvkTyt01T95DFVgzzLwk1K293dLt6C4IzR8/4Vei4ykcHiEoyzw1vynuYiFgsE9UN2+psVd7ZH/5Ln5M= Message-ID: Date: Mon, 4 Dec 2006 23:38:13 -0800 From: "Matt Reimer" To: linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: D-cache aliasing issue in cow_user_page MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 876 Lines: 16 In light of James Bottomsley's commit[1] declaring that kmap() and friends now have to take care of coherency issues, is the patch "mm: D-cache aliasing issue in cow_user_page"[2] correct, or could it potentially cause a slowdown by calling flush_dcache_page() a second time (i.e. once in an architecture-specific kmap() implementation, and once in cow_user_page())? Matt [1] http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=a6ca1b99ed434f3fb41bbed647ed36c0420501e5 [2] http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=c4ec7b0de4bc18ccb4380de638550984d9a65c25 - 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/