Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752892AbWKHBKw (ORCPT ); Tue, 7 Nov 2006 20:10:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753117AbWKHBKw (ORCPT ); Tue, 7 Nov 2006 20:10:52 -0500 Received: from gw.goop.org ([64.81.55.164]:31921 "EHLO mail.goop.org") by vger.kernel.org with ESMTP id S1752892AbWKHBKw (ORCPT ); Tue, 7 Nov 2006 20:10:52 -0500 Message-ID: <45512E9C.9030702@goop.org> Date: Tue, 07 Nov 2006 17:10:52 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.7 (X11/20061027) MIME-Version: 1.0 To: Rusty Russell CC: Andrew Morton , Zachary Amsden , Linux Kernel Mailing List Subject: Re: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush() References: <4551232A.4020203@goop.org> <1162946572.29130.9.camel@localhost.localdomain> In-Reply-To: <1162946572.29130.9.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 862 Lines: 22 Rusty Russell wrote: > On Tue, 2006-11-07 at 16:22 -0800, Jeremy Fitzhardinge wrote: > >> kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments >> which don't correspond if the vaddr is just a normal lowmem address >> (ie, not in the KMAP area). This patch makes sure that the pte is >> only cleared if kmap area was actually used for the mapping. >> > > Or in other words, if kmap_atomic() does nothing, kunmap_atomic() should > do nothing. > Sure. I guess there's no particular reason why kmap_atomic() couldn't always map, but I guess avoid the pagetable updates is worthwhile. J - 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/