From owner-freebsd-performance@FreeBSD.ORG Fri Aug 17 01:44:47 2012 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6F7B71065673 for ; Fri, 17 Aug 2012 01:44:47 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-ob0-f182.google.com (mail-ob0-f182.google.com [209.85.214.182]) by mx1.freebsd.org (Postfix) with ESMTP id 333758FC0C for ; Fri, 17 Aug 2012 01:44:46 +0000 (UTC) Received: by obbun3 with SMTP id un3so6052323obb.13 for ; Thu, 16 Aug 2012 18:44:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=gpz++Wqp5x/vCohN5B80l8MAvwUMTkMrDLSoLRVyhKI=; b=c4JVmL07RoiUzFKxTjhwCsG1VjaUgmjpNIHoj1qf6YkecuYcCnoG23CFl1lzBJ/ysp uoBAFRvjUy2cqqgoMci34ICSXpCo5sWt1bi2WSjARlasKhBSvWR6ZkQlXHfra7PMsZ5O m3mj4lFNfNndRQiAdAbw/3FkddVAa0gWYiU/H6xHqv3SuRSUCe2216YaTx91t1AhKuOb 1Y40JNMHLaQlR5U6t055J6jKKVLOduL0jUVJJzzSzy3FpZ8KD5+kw4jgBLhpdyPuavBP Us39jjggKBQbqB7VPrbwjv43IB69/DKKrRisnptCR4bwMtXU8BgKUTcQOMsNv3e60GX/ krrA== MIME-Version: 1.0 Received: by 10.182.111.39 with SMTP id if7mr2551360obb.56.1345167886251; Thu, 16 Aug 2012 18:44:46 -0700 (PDT) Received: by 10.76.142.201 with HTTP; Thu, 16 Aug 2012 18:44:46 -0700 (PDT) In-Reply-To: References: Date: Thu, 16 Aug 2012 18:44:46 -0700 Message-ID: From: Garrett Cooper To: =?ISO-8859-1?Q?Gezeala_M=2E_Bacu=F1o_II?= Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-performance@freebsd.org Subject: Re: vm.kmem_size_max and vm.kmem_size capped at 329853485875 (~307GB) 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: Fri, 17 Aug 2012 01:44:47 -0000 On Thu, Aug 16, 2012 at 5:46 PM, Gezeala M. Bacu=F1o II = wrote: > Hello fellow listers, > > On a server with 512GB RAM it appears that vm.kmem_size_max is not > being auto-tuned to use >329853485875 (~307GB). > > On this machine vm.kmem_size is equal to vm.kmem_size_max > > # from sysctl > vm.kmem_size_max: 329853485875 > vm.kmem_size: 329853485875 > > On a machine with 1GB of RAM, I have successfully set vm.kmem_size_max > to 330GB and vm.kmem_size automatically adjusts to 1GB even if I > manually set it in /boot/loader.conf. > > But on the machine with 512GB of RAM it just resets. For the machine > to boot, we need to go to the loader prompt and issue: > > OK set vm.kmem_size_max=3D"300G" > OK boot > > On all PCBSD (8,9) or FreeBSD (8.1,8.2,9) machines we have, > vm.kmem_size_max is always set to 329853485875. > > How can I increase vm.kmem_size_max to use at least 500GB? And how is > 329853485875 determined (formula)? I need to increase vm.kmem_size_max > and vm.kmem_size so I can set vfs.zfs.arc_max (ZFS ARC) to use say > 490GB. > > I'm browsing thru the source code at > http://fxr.watson.org/fxr/search?v=3DFREEBSD9&string=3Dvm.kmem_size_max > and I'm still trying to make sense of how vm.kmem_size_max is > computed. > > I have posted the same topic on forums.freebsd.org but I'm not getting > any recommendations. > > Please see the link for additional details: > http://forums.freebsd.org/showthread.php?t=3D33977 Have you tried defining VM_KMEM_SIZE_MAX to your target value? Its architecture specific BTW... see sys//include/vmparam.h -- look for `VM_KMEM_SIZE_MAX`. Cheers, -Garrett