From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933134AbXCCWwb (ORCPT ); Sat, 3 Mar 2007 17:52:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933144AbXCCWwb (ORCPT ); Sat, 3 Mar 2007 17:52:31 -0500 Received: from smtp.osdl.org ([65.172.181.24]:48542 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933134AbXCCWwa (ORCPT ); Sat, 3 Mar 2007 17:52:30 -0500 Date: Sat, 3 Mar 2007 14:52:21 -0800 From: Andrew Morton To: Rik van Riel Cc: linux-kernel@vger.kernel.org Subject: Re: userspace pagecache management tool Message-Id: <20070303145221.2a42cc0f.akpm@linux-foundation.org> In-Reply-To: <45E9F5DA.2070708@redhat.com> References: <20070303122935.f1ab0067.akpm@linux-foundation.org> <45E9DD4A.2060806@redhat.com> <20070303131204.6706a95c.akpm@linux-foundation.org> <45E9E910.2070804@redhat.com> <20070303140744.b22699dd.akpm@linux-foundation.org> <45E9F5DA.2070708@redhat.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 03 Mar 2007 17:25:30 -0500 Rik van Riel wrote: > backup program A suitable policy for a backup program would probably be to invalidate any output file(s) and to invalidate those pages of the input files which were not in cache when the backup program first opened those files. That way the backup program will have no effect on the cache state, except for the race situation where someone read an uncached file while the backup program was reading from it too. This can be added in an hour or two with no kernel changes (use mincore).