From owner-freebsd-arch@FreeBSD.ORG Fri Feb 3 19:47:17 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 1E6EC106566C; Fri, 3 Feb 2012 19:47:17 +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 801428FC13; Fri, 3 Feb 2012 19:47:16 +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 q13Jl8rd014745 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 3 Feb 2012 21:47:08 +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 q13Jl8Ss029373; Fri, 3 Feb 2012 21:47:08 +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 q13Jl8T8029372; Fri, 3 Feb 2012 21:47:08 +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: Fri, 3 Feb 2012 21:47:08 +0200 From: Konstantin Belousov To: Attilio Rao Message-ID: <20120203194708.GC3283@deviant.kiev.zoral.com.ua> References: <20120203193719.GB3283@deviant.kiev.zoral.com.ua> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7KvBbaRjXS2SFKKp" Content-Disposition: inline In-Reply-To: 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=-3.9 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: arch@freebsd.org Subject: Re: Prefaulting for i/o buffers 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: Fri, 03 Feb 2012 19:47:17 -0000 --7KvBbaRjXS2SFKKp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 03, 2012 at 07:40:37PM +0000, Attilio Rao wrote: > Do you have an ETA for reviews? When do you plan to commit this? Obviously, I cannot have an ETA for reviews, and I am not sure that I get any review at all (as usual). I think it is reasonable to commit in 2-3 weeks after the first post. > it would be valuable to get a grasp on the benchmark and refine the > performance difference as much as possible. The benchmark is trivial and available at=20 http://people.freebsd.org/~kib/misc/bench_read.c There is also a targeted test for uio functionality http://people.freebsd.org/~kib/misc/uio.c which I used together with intensive swapping workload to verify the correctness of the patch. Regarding the performance hit, I consider the < 10% on the worst case a reasonable cost for finally fixing this issue. If anybody can provide a benchmark result for e.g. postgresql tests, I will be very grateful. --7KvBbaRjXS2SFKKp Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk8sObwACgkQC3+MBN1Mb4jLCQCeIBu368//Hwq4rZmtqcUQgVRP Yq4AoONvlv43L7ABlzDggAPBNbCDz2vV =FQiX -----END PGP SIGNATURE----- --7KvBbaRjXS2SFKKp--