From owner-freebsd-hackers@FreeBSD.ORG Sat May 31 18:47:33 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 918E0106567B; Sat, 31 May 2008 18:47:33 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 466308FC31; Sat, 31 May 2008 18:47:33 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id 465EC1CC031; Sat, 31 May 2008 11:47:33 -0700 (PDT) Date: Sat, 31 May 2008 11:47:33 -0700 From: Jeremy Chadwick To: John Baldwin Message-ID: <20080531184733.GA8470@eos.sc1.parodius.com> References: <6a7033710805302252v43a7b240x66ca3f5e3dd5fda4@mail.gmail.com> <200805311249.53986.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200805311249.53986.jhb@freebsd.org> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: freebsd-hackers@freebsd.org, 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 18:47:33 -0000 On Sat, May 31, 2008 at 12:49:53PM -0400, John Baldwin wrote: > 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? On amd64 there's still a 2GB limit, re: vm.kmem_size. Increasing it to or past 2048M results in the message "kmem_suballoc(): bad status return of 3". http://lists.freebsd.org/pipermail/freebsd-stable/2008-May/042764.html -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |