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, 12 Aug 2001 18:39:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 12 Aug 2001 18:39:03 -0400 Received: from neon-gw.transmeta.com ([63.209.4.196]:29708 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Sun, 12 Aug 2001 18:38:50 -0400 To: linux-kernel@vger.kernel.org From: torvalds@transmeta.com (Linus Torvalds) Subject: Re: Performance 2.4.8 is worse than 2.4.x<8 Date: Sun, 12 Aug 2001 22:38:36 +0000 (UTC) Organization: Transmeta Corporation Message-ID: <9l70hc$1sd$1@penguin.transmeta.com> In-Reply-To: X-Trace: palladium.transmeta.com 997655938 12255 127.0.0.1 (12 Aug 2001 22:38:58 GMT) X-Complaints-To: news@transmeta.com NNTP-Posting-Date: 12 Aug 2001 22:38:58 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 , Alan Cox wrote: >> Here, disk write throughput seems to want some tweaking, and Bonnie >> doing it's rewrite test triggers a very large and persistant inactive >> shortage which shouldn't be there (imho). > >This is one of the reasons I kept the 2.4.7 vm. The 2.4.8 vm is better >than 2.4.8pre but not actually better than the older VM by feel or >measurement on my test boxes Word of warning: there are some loads on which 2.4.7 will simply lock up. If you don't want to take all the new code, at least take the changes to fs/buffer.c and refill_buffer() or whatever. With just those parts it will still end up being pitifully slow in the cases it used to lock up, but it will end up making progress and eventually recovering. (In all fairness, the load to make it go into the bad behaviour is rather unusual, and as such probably not a huge problem for most people. That's obviously also the reason why it wasn't really noticed until now - but this is, for example, apparently the cause for the "processes getting stuck in __wait_on_buffer()" bug that I know RedHat also saw under load). That said, me and Marcelo are still working on making sure it's good under _all_ loads.. Linus