From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755361Ab0CEEfc (ORCPT ); Thu, 4 Mar 2010 23:35:32 -0500 Received: from gate.crashing.org ([63.228.1.57]:42117 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755275Ab0CEEfb (ORCPT ); Thu, 4 Mar 2010 23:35:31 -0500 Subject: Re: [RFC PATCH] ARM: Assume new page cache pages have dirty D-cache From: Benjamin Herrenschmidt To: Russell King - ARM Linux Cc: Catalin Marinas , James Bottomley , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org In-Reply-To: <20100304214435.GJ13417@n2100.arm.linux.org.uk> References: <20100302172947.27766.61539.stgit@e102109-lin.cambridge.arm.com> <20100304164416.GD13417@n2100.arm.linux.org.uk> <1267727802.6526.545.camel@e102109-lin.cambridge.arm.com> <20100304214435.GJ13417@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="UTF-8" Date: Fri, 05 Mar 2010 15:32:09 +1100 Message-ID: <1267763529.22204.90.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > As I just realised, this is going to subject all pages placed into > userspace with a D cache flush - even anonymous pages, and those > which we've been careful to deal with the cache issues already (eg, > via the COW page copying code.) > > I think all the copypage functions need to set PG_dcache_clean on the > new pages once their copy has completed. > > I wonder if there's any other anonymous page creating functions which > could do with a similar treatment... Do we do anything other than COW and zero page ? clear_user_page() I suppose could deal with that if you do the cache bits there. Cheers, Ben.