From owner-freebsd-questions@FreeBSD.ORG Mon Oct 23 05:53:24 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F3CFF16A47E for ; Mon, 23 Oct 2006 05:53:23 +0000 (UTC) (envelope-from jim@centerfuse.net) Received: from mail.contexthosting.net (mail.contexthosting.net [209.120.245.124]) by mx1.FreeBSD.org (Postfix) with ESMTP id DA34643D69 for ; Mon, 23 Oct 2006 05:53:21 +0000 (GMT) (envelope-from jim@centerfuse.net) Received: from localhost (localhost [127.0.0.1]) by mail.contexthosting.net (Postfix) with ESMTP id 987D895948 for ; Mon, 23 Oct 2006 01:55:43 -0400 (EDT) Received: from mail.contexthosting.net ([209.120.245.124]) by localhost (firefly.contexthosting.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 42860-06 for ; Mon, 23 Oct 2006 01:55:43 -0400 (EDT) Received: from [192.168.1.100] (c-68-38-110-38.hsd1.pa.comcast.net [68.38.110.38]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.contexthosting.net (Postfix) with ESMTP id 4F7859595D for ; Mon, 23 Oct 2006 01:55:43 -0400 (EDT) Message-ID: <453C58BB.6030108@centerfuse.net> Date: Mon, 23 Oct 2006 01:52:59 -0400 From: Jim Keller User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at contexthosting.net Subject: general VM / KMEM tunables question X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Oct 2006 05:53:24 -0000 Trying to tune a new system (FreeBSD 6.1) for the best performance (moderately busy webserver, but nothing over the top). However, I'm having a lot of trouble finding documentation on VM sysctl tunables. I have run into the (somewhat common) issue before of running out of PV_Entries due to Apache getting busy, so my current webserver kernels all have the following in them: options KVA_PAGES=512 options PMAP_SHPGPERPROC=401 However, these values were only chosen because they seemed to fix my problem, not because I'm entirely sure they're the best possible values. How does one go about determining how many KVA_PAGES and PMAP_SHPGPERPROC to set? Also, are there sysctl OIDs for these options? Poking around google, I've seen mention of vm.pmap.pv_entry_max and vm.pmap.shgperproc, but those OIDs do not exist on my system as far as I can tell. I also have the following in my sysctl.conf, but again I'm not sure how I initially came up with these figures (though they do work), and I wanted to get a better handle on my system tuning: vm.v_free_min=8192 vm.v_free_target=16384 vm.v_free_reserved=8192 vm.v_free_severe=16384 Basically just trying to get some clues as to how to figure out (based on system config) what these values should reasonably be set to. Thanks. -Jim Keller