Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 2 Nov 2001 16:24:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 2 Nov 2001 16:23:52 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:19468 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Fri, 2 Nov 2001 16:23:35 -0500 To: linux-kernel@vger.kernel.org From: torvalds@transmeta.com (Linus Torvalds) Subject: Re: Google's mm problem - not reproduced on 2.4.13 Date: Fri, 2 Nov 2001 21:20:44 +0000 (UTC) Organization: Transmeta Corporation Message-ID: <9rv2nc$kgi$1@penguin.transmeta.com> In-Reply-To: <20011102181758Z16039-4784+420@humbolt.nl.linux.org> <9ruvkd$jh1$1@penguin.transmeta.com> <3BE30B3D.1080505@google.com> X-Trace: palladium.transmeta.com 1004736194 27011 127.0.0.1 (2 Nov 2001 21:23:14 GMT) X-Complaints-To: news@transmeta.com NNTP-Posting-Date: 2 Nov 2001 21:23:14 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 <3BE30B3D.1080505@google.com>, Ben Smith wrote: > >For 2.2 we were have a patch that increases this to 90% or 60M, but we >don't use this patch on 2.4 yet. Well, you'll also deadlock your machine if you happen to lock down the lowmemory area on x86. Sounds like a _bad_ idea. Anyway, I posted a suggested patch that should fix the behaviour, but it doesn't fix the fundamental problem with locking the wrong kinds of pages (ie you're definitely on your own if you happen to lock down most of the low 1GB of an intel machine). >Latency. We know exactly what data should remain in memory, so we're >trying to prevent the vm from paging out the wrong data. It makes a huge >difference in performance. It would be interesting to hear whether that is equally true in the new VM that doesn't necessarily page stuff out unless it can show that the memory pressure is actually from VM mappings. How big is your mlock area during real load? Still the "max the kernel will allow"? Or is that just a benchmark/test kind of thing? Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/