From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278AbXDPTEk (ORCPT ); Mon, 16 Apr 2007 15:04:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754165AbXDPTEk (ORCPT ); Mon, 16 Apr 2007 15:04:40 -0400 Received: from extu-mxob-2.symantec.com ([216.10.194.135]:31322 "EHLO extu-mxob-2.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753278AbXDPTEj (ORCPT ); Mon, 16 Apr 2007 15:04:39 -0400 X-AuditID: d80ac287-a0943bb000002c59-d0-4623c8c61242 Date: Mon, 16 Apr 2007 20:04:29 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: David Rientjes cc: Zachary Amsden , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [patch -mm] i386: use pte_update_defer in ptep_test_and_clear_{dirty,young} In-Reply-To: Message-ID: References: <46082BE6.30402@vmware.com> <461FD9BF.90609@vmware.com> <461FEF1C.5010806@vmware.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 16 Apr 2007 19:04:38.0700 (UTC) FILETIME=[14C1B6C0:01C7805A] X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Apr 2007, David Rientjes wrote: > > > Compromise patch below: would that be satisfactory to you, David? > > I really like the patch, but for perhaps a slightly different reason: > we're only flushing ranges that have been shown to need it. We aren't > completely flushing the entire mm which is likely to be excessive in > situations where we're actually using /proc/pid/clear_refs in combination > with /proc/pid/smaps for memory footprint approximation (i.e. it's on a > fine granularity). It would be more of a reason to like the patch, if more architectures actually implemented flush_tlb_range as anything different from flush_tlb_mm ;) Sadly, few can do better than flush_tlb_mm: ia64 is the exception I remember, and maybe a couple of others. I put flush_tlb_range there merely because it seems more appropriate, but it's rather deceptive. Hugh