From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 16 Sep 2001 01:32:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 16 Sep 2001 01:32:02 -0400 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:6922 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Sun, 16 Sep 2001 01:31:56 -0400 To: linux-kernel@vger.kernel.org From: torvalds@transmeta.com (Linus Torvalds) Subject: Re: broken VM in 2.4.10-pre9 Date: Sun, 16 Sep 2001 05:31:11 +0000 (UTC) Organization: Transmeta Corporation Message-ID: <9o1dev$23l$1@penguin.transmeta.com> In-Reply-To: X-Trace: palladium.transmeta.com 1000618315 17555 127.0.0.1 (16 Sep 2001 05:31:55 GMT) X-Complaints-To: news@transmeta.com NNTP-Posting-Date: 16 Sep 2001 05:31:55 GMT Cache-Post-Path: palladium.transmeta.com!unknown@penguin.transmeta.com X-Cache: nntpcache 2.4.0b5 (see http://www.nntpcache.org/) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article , Peter Magnusson wrote: > >2.4.10-pre4: quite ok VM, but put little more on the swap than 2.4.7 >2.4.10-pre8: not good Ehh.. There are _no_ VM changes that I can see between pre4 and pre8. >2.4.10-pre9: not good ... Linux didnt had used any swap at all, then i > unrared two very large files at the same time. And now 104 > Mbyte swap is used! :-( 2.4.7 didnt do like this. > Best is to use the swap as little as possible. .. and there are none between pre8 and pre9. Basically, it sounds lik eyou have tested different loads on different kernels, and some loads are nice and others are not. Also note that the amount of "swap used" is totally meaningless in 2.4.x. The 2.4.x kernel will _allocate_ the swap backing store much earlier than 2.2.x, but that doesn't actuall ymean that it does any of the IO. Indeed, allocating the swap backing store just means that the swap pages are then kept track of, so that they can be aged along with other stores. So whether Linux uses swap or not is a 100% meaningless indicator of "goodness". The only thing that matters is how well the job gets done, ie was it reasonably responsive, and did the big untars finish quickly.. Don't look at how many pages of swap were used. That's a statistic, nothing more. Linus