From owner-freebsd-performance@FreeBSD.ORG Sun Aug 7 18:57:47 2005 Return-Path: X-Original-To: freebsd-performance@FreeBSD.org Delivered-To: freebsd-performance@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 61A4B16A41F for ; Sun, 7 Aug 2005 18:57:47 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0AC2943D48 for ; Sun, 7 Aug 2005 18:57:47 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 71C295CBA; Sun, 7 Aug 2005 14:57:46 -0400 (EDT) Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 02474-10; Sun, 7 Aug 2005 14:57:45 -0400 (EDT) Received: from [192.168.1.3] (pool-68-161-79-217.ny325.east.verizon.net [68.161.79.217]) by pi.codefab.com (Postfix) with ESMTP id 157EE5C68; Sun, 7 Aug 2005 14:57:44 -0400 (EDT) Message-ID: <42F659AE.80905@mac.com> Date: Sun, 07 Aug 2005 14:57:50 -0400 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.11) Gecko/20050801 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Xin LI References: <20050807184707.GA61714@frontfree.net> In-Reply-To: <20050807184707.GA61714@frontfree.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at codefab.com Cc: freebsd-performance@FreeBSD.org Subject: Re: [RFC] Bumping ufs.dirhash_maxmem to a larger value? X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 07 Aug 2005 18:57:47 -0000 Xin LI wrote: > It seems that vfs.ufs.dirhash_maxmem is set to 2MB. I think this value > is slightly too small for modern machines: [ ... ] > My proposal is to increase the default dirhash_maxmem value to at least > 32MB or 64MB. Any objections? You are undoubtedly right that allocating only 2MB for dirhash on a modern machine which has, for example, 1GB of RAM is too small. On the other hand, I've got several firewall boxes with only 128MB, and it's not reasonable to simply dedicate up to 64MB (half!) to dirhash without paying more attention to the amount of physical memory that is actually available. How big should dirhash_maxmem be? 5-10% of available RAM, perhaps? -- -Chuck