From owner-freebsd-hackers@FreeBSD.ORG Mon Oct 25 09:42:03 2010 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 5A5851065674 for ; Mon, 25 Oct 2010 09:42:03 +0000 (UTC) (envelope-from peterjeremy@acm.org) Received: from fallbackmx06.syd.optusnet.com.au (fallbackmx06.syd.optusnet.com.au [211.29.132.8]) by mx1.freebsd.org (Postfix) with ESMTP id BF0C68FC16 for ; Mon, 25 Oct 2010 09:42:02 +0000 (UTC) Received: from mail36.syd.optusnet.com.au (mail36.syd.optusnet.com.au [211.29.133.76]) by fallbackmx06.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id o9P9W0tH029726 for ; Mon, 25 Oct 2010 20:32:00 +1100 Received: from server.vk2pj.dyndns.org (c220-239-116-103.belrs4.nsw.optusnet.com.au [220.239.116.103]) by mail36.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id o9P9Vneu030078 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 25 Oct 2010 20:31:51 +1100 X-Bogosity: Ham, spamicity=0.000000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.4/8.14.4) with ESMTP id o9P9VnsS067946; Mon, 25 Oct 2010 20:31:49 +1100 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.4/8.14.4/Submit) id o9P9Vn24067945; Mon, 25 Oct 2010 20:31:49 +1100 (EST) (envelope-from peter) Date: Mon, 25 Oct 2010 20:31:49 +1100 From: Peter Jeremy To: Jean-Francois Dockes Message-ID: <20101025093149.GA67314@server.vk2pj.dyndns.org> References: <4CC44E5B.9040902@infracaninophile.co.uk> <20101024152835.GA62748@muon.cran.org.uk> <19652.22833.731361.647776@y.dockes.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2oS5YaxWCcQjTEyO" Content-Disposition: inline In-Reply-To: <19652.22833.731361.647776@y.dockes.com> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-hackers@freebsd.org Subject: Re: dump cache performance 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: Mon, 25 Oct 2010 09:42:03 -0000 --2oS5YaxWCcQjTEyO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2010-Oct-24 18:05:05 +0200, Jean-Francois Dockes wrote: >It appears that modifying dump to use a shared cache in a very simple way >(move the control structures to the shared segment and perform simple lock= ing) >yields substantial speed increases. Indeed. That's better than I expected. >Would someone be interested in reviewing the patch and/or perform >more tests ? I've mostly convered to ZFS but still have UFS root (which is basically a full base install without /var but including /usr/src - 94k inodes and 1.7GB). I've run both the 8-stable ("stable") and patched ("jfd") dump= =20 alternately 4 times with 50/250MB cache with the following results: x stable + jfd +------------------------------------------------------------+ | +| | +| | x +| |x xx +| ||AM A| +------------------------------------------------------------+ N Min Max Median Avg Stddev x 4 9413 9673 9568 9555.5 107.12143 + 4 15359 15359 15359 15359 0 Difference at 95.0% confidence 5803.5 +/- 131.063 60.7347% +/- 1.3716% (Student's t, pooled s =3D 75.7463) --=20 Peter Jeremy --2oS5YaxWCcQjTEyO Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (FreeBSD) iEYEARECAAYFAkzFToUACgkQ/opHv/APuIdK3QCeJ/Wpki/DqQwnn1mfmtCWgedO gBUAnR0CYT9O4VUSsyW0/89WGEVTFmcf =mLvt -----END PGP SIGNATURE----- --2oS5YaxWCcQjTEyO--