From owner-freebsd-hackers@FreeBSD.ORG Sun Jun 8 05:58:41 2008 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5E5F2106567A for ; Sun, 8 Jun 2008 05:58:41 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (skuns.zoral.com.ua [91.193.166.194]) by mx1.freebsd.org (Postfix) with ESMTP id DBC6A8FC14 for ; Sun, 8 Jun 2008 05:58:40 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m585Qr8b009469 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 8 Jun 2008 08:26:53 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m585QrZu027936; Sun, 8 Jun 2008 08:26:53 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2/Submit) id m585Qr74027931; Sun, 8 Jun 2008 08:26:53 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 8 Jun 2008 08:26:53 +0300 From: Kostik Belousov To: Alan Cox Message-ID: <20080608052653.GS94309@deviant.kiev.zoral.com.ua> References: <484B20E7.2040009@cs.rice.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qZLIv6EoKi7YuaSc" Content-Disposition: inline In-Reply-To: <484B20E7.2040009@cs.rice.edu> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: ClamAV version 0.91.2, clamav-milter version 0.91.2 on skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on skuns.kiev.zoral.com.ua Cc: hackers@freebsd.org Subject: Re: Increasing KVM on amd64 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: Sun, 08 Jun 2008 05:58:41 -0000 --qZLIv6EoKi7YuaSc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jun 07, 2008 at 06:59:35PM -0500, Alan Cox wrote: > You can download a patch from=20 > http://www.cs.rice.edu/~alc/amd64_kvm_6GB.patch that increases amd64's=20 > kernel virtual address space to 6GB. This patch also increases the=20 > default for the kmem map to almost 2GB. I believe that kernel loadable= =20 > modules still work. However, I suspect that mini-dumps are broken. The amd64 modules text/data/bss virtual addresses are allocated from the=20 kernel_map (link_elf_obj.c, link_elf_load_file). Now, the lower end of the kernel_map is top-6Gb. Kernel code (both kernel proper and modules) is compiled for "kernel memory model", according to the gcc info: `-mcmodel=3Dkernel' Generate code for the kernel code model. The kernel runs in the negative 2 GB of the address space. This model has to be used for Linux kernel code. I suspect we have a problem there. >=20 > I don't plan on committing this patch in its current form. Some of the= =20 > changes are done in a hackish way. I am, however, curious to hear=20 > whether or not it works for you. >=20 > Alan --qZLIv6EoKi7YuaSc Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkhLbZwACgkQC3+MBN1Mb4i9BgCgtmAc3vZy0zyesiRVFBIcZ1Qs pLEAoM5TMKupttnKAQlmx6Iam0tEb4ND =79Y/ -----END PGP SIGNATURE----- --qZLIv6EoKi7YuaSc--