From owner-freebsd-hackers@FreeBSD.ORG Sat May 31 16:52:51 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 47BD1106566C for ; Sat, 31 May 2008 16:52:51 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 24FE68FC1A for ; Sat, 31 May 2008 16:52:51 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from zion.baldwin.cx (server.baldwin.cx [208.65.91.234]) by elvis.mu.org (Postfix) with ESMTP id CA2111A4D83; Sat, 31 May 2008 09:52:50 -0700 (PDT) From: John Baldwin To: freebsd-hackers@freebsd.org Date: Sat, 31 May 2008 12:49:53 -0400 User-Agent: KMail/1.9.7 References: <6a7033710805302252v43a7b240x66ca3f5e3dd5fda4@mail.gmail.com> In-Reply-To: <6a7033710805302252v43a7b240x66ca3f5e3dd5fda4@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200805311249.53986.jhb@freebsd.org> Cc: Tz-Huan Huang Subject: Re: Is there any way to increase the KVM? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 31 May 2008 16:52:51 -0000 On Saturday 31 May 2008 01:52:56 am Tz-Huan Huang wrote: > Hi, > > Our nfs server is running 7-stable/amd64 with 8G ram, the size of zfs > pool is 12T. We have set vm.kmem_size and vm.kmem_size_max to > 1.5G, but the kernel still panics by "kmem_map too small" often. > According to [1], the limitation is not only by the loader (is it fixed > now?) but also by the default layout of KVM. [2] points a way to increase > the KVM, but we get the similar linking error. > > Is there any standard way to modify the layout of KVM? For example, we > may want to set KVM to 6G and leave the 2G for user space usage. On i386 you only have 4GB of virtual address space period. For amd64 you can jack up KVM just fine AFAIK. The mcmodel=kernel stuff should only affect global variables (so .data and .bss) and not malloc'd stuff. Have you tried increasing the KVM size and seeing what happens? -- John Baldwin