From owner-freebsd-current@FreeBSD.ORG Tue May 9 18:13:07 2006 Return-Path: X-Original-To: current@FreeBSD.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8E78316A93C; Tue, 9 May 2006 18:13:07 +0000 (UTC) (envelope-from grog@lemis.com) Received: from ext-gw.lemis.com (ext-gw.lemis.com [150.101.14.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id C20C943D70; Tue, 9 May 2006 18:13:06 +0000 (GMT) (envelope-from grog@lemis.com) Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.135]) by ext-gw.lemis.com (Postfix) with ESMTP id C9E56131DE0; Wed, 10 May 2006 03:43:05 +0930 (CST) Received: from eucla.lemis.com (wantadilla.lemis.com [192.109.197.135]) by wantadilla.lemis.com (Postfix) with ESMTP id 394B384632; Wed, 10 May 2006 03:43:05 +0930 (CST) Received: from eucla.lemis.com (localhost [127.0.0.1]) by eucla.lemis.com (Postfix) with ESMTP id CFEA2D5DA4; Tue, 9 May 2006 11:13:03 -0700 (PDT) Received: (from grog@localhost) by eucla.lemis.com (8.13.6/8.13.4/Submit) id k49ID3FL005063; Tue, 9 May 2006 11:13:03 -0700 (PDT) (envelope-from grog) Date: Tue, 9 May 2006 11:13:02 -0700 From: "Greg 'groggy' Lehey" To: Kris Kennaway Message-ID: <20060509181302.GD3636@eucla.lemis.com> References: <20060506150622.C17611@fledge.watson.org> <20060506221908.GB51268@xor.obsecurity.org> <20060507210426.GA4422@xor.obsecurity.org> <20060507214153.GA5275@xor.obsecurity.org> <20060507230430.GA6872@xor.obsecurity.org> <20060508065207.GA20386@xor.obsecurity.org> <20060509004328.GB55852@xor.obsecurity.org> <20060509011109.GA57060@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="IMjqdzrDRly81ofr" Content-Disposition: inline In-Reply-To: <20060509011109.GA57060@xor.obsecurity.org> User-Agent: Mutt/1.4.2.1i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 VoIP: sip:0871270137@sip.internode.on.net WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 Cc: Robert Watson , performance@FreeBSD.org, current@FreeBSD.org Subject: Re: Fine-grained locking for POSIX local sockets (UNIX domain sockets) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 May 2006 18:13:11 -0000 --IMjqdzrDRly81ofr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Monday, 8 May 2006 at 21:11:09 -0400, Kris Kennaway wrote: > On Mon, May 08, 2006 at 08:43:28PM -0400, Kris Kennaway wrote: >> On Mon, May 08, 2006 at 02:52:07AM -0400, Kris Kennaway wrote: >>> OK, David's patch fixes the umtx thundering herd (and seems to give a >>> 4-6% boost). I also fixed a thundering herd in FILEDESC_UNLOCK (which >>> was also waking up 2-7 CPUs at once about 30% of the time) by doing >>> s/wakeup/wakeup_one/. This did not seem to give a performance impact >>> on this test though. >> >> Turning down kern.hz from 1000 to 100 also made a big difference on 12 >> CPUs (+6.1%). >> >> Note also that the system is no less than 40% idle during the runs (at >> any load), so the bottlenecks are serious. > > top -H shows the threads mostly in umtx state. This doesn't lend much support to the idea that the gettimeofday() calls are a bottleneck. I've just been through the code, but if there are any mutexes acquired there, I missed them. Greg -- See complete headers for address and phone numbers --IMjqdzrDRly81ofr Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFEYNutIubykFB6QiMRAhriAJ9eot/N1vVl0VsXdZX0JocYC7/qxACfSM+V GyLMmRNfOAhK+sLjc7M4YsQ= =vjXK -----END PGP SIGNATURE----- --IMjqdzrDRly81ofr--