Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932204AbZG1XyL (ORCPT ); Tue, 28 Jul 2009 19:54:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932192AbZG1XyJ (ORCPT ); Tue, 28 Jul 2009 19:54:09 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53572 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932199AbZG1XyG (ORCPT ); Tue, 28 Jul 2009 19:54:06 -0400 Date: Tue, 28 Jul 2009 16:52:45 -0700 From: Andrew Morton To: "Moussa A. Ba" Cc: linux-kernel@vger.kernel.org, rientjes@google.com, xiyou.wangcong@gmail.com, adobriyan@gmail.com, mpm@selenic.com, mel@csn.ul.ie, yinghan@google.com, npiggin@suse.de, jaredeh@gmail.com Subject: Re: [PATCH 1/1] pagemap clear_refs: modify to specify anon or mapped vma clearing Message-Id: <20090728165245.65d5cb23.akpm@linux-foundation.org> In-Reply-To: <4A6F8115.7000500@gmail.com> References: <4A693122.6060503@gmail.com> <20090724083926.GA6372@cr0.nay.redhat.com> <4A6E0BD6.50102@gmail.com> <7928e7bd0907271514y699d1de4j54f9c562b94ef0cc@mail.gmail.com> <7928e7bd0907271638x5ddbfd2ckba2802338a33765a@mail.gmail.com> <4A6F2AF4.6050505@gmail.com> <4A6F8115.7000500@gmail.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1007 Lines: 23 On Tue, 28 Jul 2009 15:52:05 -0700 "Moussa A. Ba" wrote: > This patch adds anonymous and file backed filters to the clear_refs interface. > echo 1 > /proc/PID/clear_refs resets the bits on all pages > echo 2 > /proc/PID/clear_refs resets the bits on anonymous pages only > echo 3 > /proc/PID/clear_refs resets the bits on file backed pages only > Any other value is ignored The changelog is missing any rationale for making this change. Originally we were told that it "makes the clear_refs proc interface a bit more versatile", but that's a bit thin. How do we justify making this change to Linux? What value does it have? Can you describe a usage scenario which would help people understand the usefulness of the change? Thanks. -- 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/