From owner-freebsd-net@FreeBSD.ORG Sun Nov 25 09:46:35 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8076D16A420; Sun, 25 Nov 2007 09:46:35 +0000 (UTC) (envelope-from max@love2party.net) Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.183]) by mx1.freebsd.org (Postfix) with ESMTP id EB48813C465; Sun, 25 Nov 2007 09:46:34 +0000 (UTC) (envelope-from max@love2party.net) Received: from amd64.laiers.local (dslb-088-066-008-048.pools.arcor-ip.net [88.66.8.48]) by mrelayeu.kundenserver.de (node=mrelayeu0) with ESMTP (Nemesis) id 0MKwh2-1IwE4L3d42-0003IA; Sun, 25 Nov 2007 10:46:30 +0100 From: Max Laier Organization: FreeBSD To: Darren Reed Date: Sun, 25 Nov 2007 10:47:37 +0100 User-Agent: KMail/1.9.7 References: <200711231232.04447.max@love2party.net> <200711242006.04753.max@love2party.net> <47491532.1050600@freebsd.org> In-Reply-To: <47491532.1050600@freebsd.org> X-Face: ,,8R(x[kmU]tKN@>gtH1yQE4aslGdu+2]; R]*pL,U>^H?)gW@49@wdJ`H<=?utf-8?q?=25=7D*=5FBD=0A=09U=5For=3D=5CmOZf764=26nYj=3DJYbR1PW0ud?=>|!~,,CPC.1-D$FG@0h3#'5"k{V]a~.<=?utf-8?q?mZ=7D44=23Se=7Em=0A=09Fe=7E=5C=5DX5B=5D=5Fxj?=(ykz9QKMw_l0C2AQ]}Ym8)fU MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart10973900.OHRaPakIth"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200711251047.44778.max@love2party.net> X-Provags-ID: V01U2FsdGVkX1/Pjn7Tepzmto0DnpfWOXKQLChmsDCcQ5gy/BK 6sWE88OcrueblRgYbSBcYn4OC9mpvpFy+EYOMoHbn2LWcUGn/S 3ZAVx2imT5S+Lzd8ZPIyfLo91pOnacXHqR6qsEozUc= Cc: freebsd-net@freebsd.org, freebsd-current@freebsd.org, Robert Watson Subject: Re: Switch pfil(9) to rmlocks X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 25 Nov 2007 09:46:35 -0000 --nextPart10973900.OHRaPakIth Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Sunday 25 November 2007, Darren Reed wrote: > Max Laier wrote: > > On Friday 23 November 2007, Robert Watson wrote: > > > On Fri, 23 Nov 2007, Max Laier wrote: > > > > attached is a diff to switch the pfil(9) subsystem to rmlocks, > > > > which are more suited for the task. I'd like some exposure > > > > before doing the switch, but I don't expect any fallout. This > > > > email is going through the patched pfil already - twice. > > > > > > Max, > > > > > > Have you done performance measurements that show rmlocks to be a > > > win in this scenario? I did some patchs for UNIX domain sockets to > > > replace the rwlock there but it appeared not to have a measurable > > > impact on SQL benchmarks, presumbaly because the read/write blend > > > wasn't right and/or that wasnt a significant source of overhead in > > > the benchmark. I'd anticipate a much more measurable improvement > > > for pfil, but would be interested in learning how much is seen? > > > > I had to roll an artificial benchmark in order to see a significant > > change (attached - it's a hack!). > > > > Using 3 threads on a 4 CPU machine I get the following results: > > null hook: ~13% +/- 2 > > mtx hook: up to 40% [*] > > rw hook: ~5% +/- 1 > > rm hook: ~35% +/- 5 > > Is that 13%/5%/35% faster or slower or improvement or degradation? > If "rw hook" (using rwlock like we have today?) is 5%, whas is the > baseline? > > I'm expecting that at least one of these should be a 0%... Sorry for the sparse explanation. All numbers above are gain with rmlocks= =20 i.e. rmlocks are faster in all scenarios. The test cases are different=20 hook functions. Every hook has a DELAY(1) and a lock/unlock call around=20 it of the respective lock type. read lock acquisitions for rw and rm. =20 Please look at the code I posted a bit later for more details. =2D-=20 /"\ Best regards, | mlaier@freebsd.org \ / Max Laier | ICQ #67774661 X http://pf4freebsd.love2party.net/ | mlaier@EFnet / \ ASCII Ribbon Campaign | Against HTML Mail and News --nextPart10973900.OHRaPakIth Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQBHSUTAXyyEoT62BG0RAgIyAJ9W1OBtLFLCX/wtiTxnfpOwyo6HeQCdEp+W NTn8ZfHcfE6DDb4oDvJZAmQ= =6v2D -----END PGP SIGNATURE----- --nextPart10973900.OHRaPakIth--