From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422655AbXCNU4q (ORCPT ); Wed, 14 Mar 2007 16:56:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422660AbXCNU4q (ORCPT ); Wed, 14 Mar 2007 16:56:46 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:34905 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422655AbXCNU4p (ORCPT ); Wed, 14 Mar 2007 16:56:45 -0400 Subject: Re: [PATCH] mm/filemap.c: unconditionally call mark_page_accessed From: Dave Kleikamp To: Ashif Harji Cc: linux-mm@kvack.org, Nick Piggin , Jan Kara , linux-kernel@vger.kernel.org, akpm@linux-foundation.org In-Reply-To: References: <20070312142012.GH30777@atrey.karlin.mff.cuni.cz> <20070312143900.GB6016@wotan.suse.de> <20070312151355.GB23532@duck.suse.cz> <20070312173500.GF23532@duck.suse.cz> <20070313185554.GA5105@duck.suse.cz> Content-Type: text/plain Date: Wed, 14 Mar 2007 15:55:41 -0500 Message-Id: <1173905741.8763.36.camel@kleikamp.austin.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-03-14 at 15:58 -0400, Ashif Harji wrote: > This patch unconditionally calls mark_page_accessed to prevent pages, > especially for small files, from being evicted from the page cache despite > frequent access. I guess the downside to this is if a reader is reading a large file, or several files, sequentially with a small read size (smaller than PAGE_SIZE), the pages will be marked active after just one read pass. My gut says the benefits of this patch outweigh the cost. I would expect real-world backup apps, etc. to read at least PAGE_SIZE. Shaggy -- David Kleikamp IBM Linux Technology Center