Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946134AbWJSSNh (ORCPT ); Thu, 19 Oct 2006 14:13:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946299AbWJSSNh (ORCPT ); Thu, 19 Oct 2006 14:13:37 -0400 Received: from ftp.linux-mips.org ([194.74.144.162]:41953 "EHLO ftp.linux-mips.org") by vger.kernel.org with ESMTP id S1946134AbWJSSNg (ORCPT ); Thu, 19 Oct 2006 14:13:36 -0400 Date: Thu, 19 Oct 2006 19:13:46 +0100 From: Ralf Baechle To: Nick Piggin Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Atsushi Nemoto Subject: Re: [PATCH 1/3] Fix COW D-cache aliasing on fork Message-ID: <20061019181346.GA5421@linux-mips.org> References: <1161275748231-git-send-email-ralf@linux-mips.org> <4537B9FB.7050303@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4537B9FB.7050303@yahoo.com.au> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 755 Lines: 17 On Fri, Oct 20, 2006 at 03:46:35AM +1000, Nick Piggin wrote: > What about if you just flush the caches after write protecting all > COW pages? Would that work? Simpler? Better performance? (I don't know) That would require changing the order of cache flush and tlb flush. To keep certain architectures that require a valid translation in the TLB the cacheflush has to be done first. Not sure if those architectures need a writeable mapping for dirty cachelines - I think hypersparc was one of them. Ralf - 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/