From owner-freebsd-arch@FreeBSD.ORG Sun Feb 26 14:52:22 2012 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8926C1065672; Sun, 26 Feb 2012 14:52:22 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 01CA58FC08; Sun, 26 Feb 2012 14:52:21 +0000 (UTC) Received: from skuns.kiev.zoral.com.ua (localhost [127.0.0.1]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id q1QEqHsn071070; Sun, 26 Feb 2012 16:52:17 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5) with ESMTP id q1QEqHNc027413; Sun, 26 Feb 2012 16:52:17 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5/Submit) id q1QEqH7W027412; Sun, 26 Feb 2012 16:52:17 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 26 Feb 2012 16:52:17 +0200 From: Konstantin Belousov To: arch@freebsd.org Message-ID: <20120226145217.GV55074@deviant.kiev.zoral.com.ua> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UjTPyfxZRWWsQMwo" Content-Disposition: inline User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.0 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: Subject: Prefaulting for i/o buffers: v2.0 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 26 Feb 2012 14:52:22 -0000 --UjTPyfxZRWWsQMwo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline I started a new thread since I do not want this message to interfere with some side discussions caused by my initial letter. I continued development and refinement of the original patch. The latest version is available at http://people.freebsd.org/~kib/misc/vm1.11.patch. Since first announce, intermediate versions of the patch were reviewed by attilio, mdf and pjd. A version of the patch was tested and benchmarked by flo, which apparently shown no difference for a postgresql benchmark. I fixed several shameful bugs, in particular, buildworld now successfully finishes on the patched kernel and working directory both on UFS and newnfs mounts. Apparently, bsdar(1) provides an excellent functional test for the patch. Most significant difference with previous variants is that now the use of prefaulting is opt-in. I discovered that typical filesystem does not handle uiomove() errors gracefully. Only UFS and newnfs are switched to use prefaulting. The newnfs client was changed to properly handle uiomove() failures and to not cause user data loss on EFAULT (this is also applicable for the stock svn sources). Corresponding changes were reviewed by rmacklem. My own feel is that vm1.11.patch is ready to be committed. This is a notification to allow more people to take a look and provide the pre-commit opinions. Thanks. --UjTPyfxZRWWsQMwo Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk9KRyEACgkQC3+MBN1Mb4gGIQCgpj2DAyn+TCL0qAeENcoSahWs wG0Anj/7RrFNMnQsngTAokRw27yduMk3 =sknu -----END PGP SIGNATURE----- --UjTPyfxZRWWsQMwo--