From owner-freebsd-performance@FreeBSD.ORG Fri Aug 17 01:47:30 2012 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E4C331065672 for ; Fri, 17 Aug 2012 01:47:30 +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 A7CDB8FC12 for ; Fri, 17 Aug 2012 01:47:30 +0000 (UTC) Received: by obbun3 with SMTP id un3so6056855obb.13 for ; Thu, 16 Aug 2012 18:47:30 -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=9K3ymMfRTl0BRyJWhbp6zUjm2I3BADpZQP69gu4yN00=; b=TfPxxzLW/FHIZ5mMHziIAR7zLoAfoOA2x5QxJmdpeUTTcKFYKKJqsUAYwXIJfzsa6M lxcCQhrVct9oL0QfVDoYboDQhuD96ziZVm/fY9oDQW+E5vesNz3x2ubhvTJCuptr+Uwx C708ItuHQXr0U9cnfBfT0WVs+yP7TWZF6sEf+CSB0TzbMN4qn4YjL5y62XDBXW9kPzUB qqvwbXygeJyGnhoBsT2fARAdF/sU4W5eEBfoHekjSh0gMmJyYuo3hmOxDpyabnorrGWQ cH6Kh5MtSRDhPNqlWhxMQHhh0kI8YpGRvLou2kVfjunnyh+dnXMxx+pFwo337O0Sp8m2 F+MA== MIME-Version: 1.0 Received: by 10.60.28.101 with SMTP id a5mr2599047oeh.69.1345168050024; Thu, 16 Aug 2012 18:47:30 -0700 (PDT) Received: by 10.76.142.201 with HTTP; Thu, 16 Aug 2012 18:47:29 -0700 (PDT) In-Reply-To: References: Date: Thu, 16 Aug 2012 18:47:29 -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 01:47:31 -0000 On Thu, Aug 16, 2012 at 6:44 PM, Garrett Cooper wrote: > 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`. Also, it's a tunable, not a sysctl... so you need to set the value in /boot/loader.conf . -Garrett