From owner-freebsd-current@FreeBSD.ORG Wed Jun 21 18:35:46 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 3AA8016A479 for ; Wed, 21 Jun 2006 18:35:46 +0000 (UTC) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (gate.funkthat.com [69.17.45.168]) by mx1.FreeBSD.org (Postfix) with ESMTP id C263043D48 for ; Wed, 21 Jun 2006 18:35:45 +0000 (GMT) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (zy3enuigcji9jhis@localhost.funkthat.com [127.0.0.1]) by hydrogen.funkthat.com (8.13.6/8.13.3) with ESMTP id k5LIZiex085599; Wed, 21 Jun 2006 11:35:44 -0700 (PDT) (envelope-from jmg@hydrogen.funkthat.com) Received: (from jmg@localhost) by hydrogen.funkthat.com (8.13.6/8.13.3/Submit) id k5LIZhFc085598; Wed, 21 Jun 2006 11:35:43 -0700 (PDT) (envelope-from jmg) Date: Wed, 21 Jun 2006 11:35:43 -0700 From: John-Mark Gurney To: Kris Kennaway Message-ID: <20060621183543.GC82074@funkthat.com> Mail-Followup-To: Kris Kennaway , current@FreeBSD.org References: <20060612054115.GA42379@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060612054115.GA42379@xor.obsecurity.org> User-Agent: Mutt/1.4.2.1i X-Operating-System: FreeBSD 5.4-RELEASE-p6 i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html Cc: current@FreeBSD.org Subject: Re: FILEDESC_LOCK() implementation X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: John-Mark Gurney List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Jun 2006 18:35:46 -0000 Kris Kennaway wrote this message on Mon, Jun 12, 2006 at 01:41 -0400: > I fixed mutex profiling to a) not be as wrong and b) not suck so very > much, and here is a revised profiling trace from mysql supersmack on a > 12 cpu E4500, sorted by ratio of cnt_lock/count; filedesc lock > contention (via FILEDESC_[UN]LOCK()) is the major mutex contention > problem. Should we also look at breaking down filedesc lock to have multiple locks over the range? I am thinking of writing a program that will have 32 threads (sun4v) and all threads will be doing heavy i/o, and will be even more heavily contested on FILEDESC than the supersmack benchmark would be... Though this doesn't solve the problem of all 32 threads trying to do i/o on a fd in the same block though... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."