From owner-freebsd-current@FreeBSD.ORG Tue Apr 20 08:17:35 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8BD4F16A4CE; Tue, 20 Apr 2004 08:17:35 -0700 (PDT) Received: from schlepper.zs64.net (schlepper.zs64.net [212.12.50.230]) by mx1.FreeBSD.org (Postfix) with ESMTP id 834FF43D3F; Tue, 20 Apr 2004 08:17:34 -0700 (PDT) (envelope-from stb@lassitu.de) Received: from [127.0.0.1] (schlepper [212.12.50.230]) by schlepper.zs64.net (8.12.10/8.11.1) with ESMTP id i3KFHX7D023234; Tue, 20 Apr 2004 17:17:33 +0200 (CEST) (envelope-from stb@lassitu.de) In-Reply-To: <20040420134021.GD64842@ip.net.ua> References: <20040420134021.GD64842@ip.net.ua> Mime-Version: 1.0 (Apple Message framework v613) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Stefan Bethke Date: Tue, 20 Apr 2004 17:17:31 +0200 To: Ruslan Ermilov X-Mailer: Apple Mail (2.613) cc: freebsd-current@freebsd.org Subject: Re: Tuning KVA_PAGES / kmem? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Apr 2004 15:17:35 -0000 Am 20.04.2004 um 15:40 schrieb Ruslan Ermilov: > On Tue, Apr 20, 2004 at 01:14:52PM +0200, Stefan Bethke wrote: >> I dug through the archives, and I found some hints that with >>2 GB >> RAM, the auto-tuning might produce undesirable results, so I might >> need >> to tune KVA_PAGES to reserve more address space for the kernel, or >> fiddle with VM_KMEM_SIZE_MAX, VM_KMEM_SIZE_SCALE, or some vm sysctls. >> >> Can someone point me in the right direction? >> > See sys/i386/conf/NOTES, when it talks about KVA_PAGES, for the > starters. Thanks, I already looked at that, but I'd be interested in some recommendations on which values for the various tunables would be better than the defaults. NOTES has this to say about KVA_PAGES: # Change the size of the kernel virtual address space. Due to # constraints in loader(8) on i386, this must be a multiple of 4. # 256 = 1 GB of kernel address space. Increasing this also causes # a reduction of the address space in user processes. 512 splits # the 4GB cpu address space in half (2GB user, 2GB kernel). # options KVA_PAGES=260 This neatly explains what changing the default will affect, but not really what to set it to given a certain amount of physical memory. Certainly, there must be people running -current with 4 or 6 GB or RAM, and with some advice whcih parameters work for them? Thanks again, Stefan -- Stefan Bethke Fon +49 170 346 0140