From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269257AbUIHRcm (ORCPT ); Wed, 8 Sep 2004 13:32:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269261AbUIHRcm (ORCPT ); Wed, 8 Sep 2004 13:32:42 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.105]:62365 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S269257AbUIHRc1 (ORCPT ); Wed, 8 Sep 2004 13:32:27 -0400 Date: Wed, 08 Sep 2004 10:31:13 -0700 From: "Martin J. Bligh" To: Ray Bryant , Marcelo Tosatti cc: Con Kolivas , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, riel@redhat.com, piggin@cyberone.com.au Subject: Re: swapping and the value of /proc/sys/vm/swappiness Message-ID: <5860000.1094664673@flay> In-Reply-To: <413F1518.7050608@sgi.com> References: <413CB661.6030303@sgi.com> <20040906162740.54a5d6c9.akpm@osdl.org> <20040907000304.GA8083@logos.cnet> <20040907212051.GC3492@logos.cnet> <413F1518.7050608@sgi.com> X-Mailer: Mulberry/2.1.2 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > It seems to me that the 5% number in there is more or less arbitrary. > If we are on a big memory Altix (4 TB), 5% of memory would be 200 GB. > That is a lot of page cache. For HPC, maybe. For a fileserver, it might be far too little. That's the trouble ... it's all dependant on the workload. Personally, I'd prefer to get rid of manual tweakables (which are a pain in the ass in the field anyway), and try to have the kernel react to what the customer is doing. I guess we can leave them there for overrides, but a self-tunable default would be most desirable. For instance, would be nice if we started doing writeback to the spindles that weren't busy much earlier than if the disks were thrashing. M.