From owner-freebsd-hackers@FreeBSD.ORG Mon Nov 26 09:57:39 2007 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 E385616A46E; Mon, 26 Nov 2007 09:57:39 +0000 (UTC) (envelope-from gregoryd.freebsd@free.fr) Received: from postfix2-g20.free.fr (postfix2-g20.free.fr [212.27.60.43]) by mx1.freebsd.org (Postfix) with ESMTP id 8E4C113C478; Mon, 26 Nov 2007 09:57:38 +0000 (UTC) (envelope-from gregoryd.freebsd@free.fr) Received: from smtp8-g19.free.fr (smtp8-g19.free.fr [212.27.42.65]) by postfix2-g20.free.fr (Postfix) with ESMTP id 730C51F82214; Mon, 26 Nov 2007 08:32:27 +0100 (CET) Received: from smtp8-g19.free.fr (localhost [127.0.0.1]) by smtp8-g19.free.fr (Postfix) with ESMTP id 1925817F5AE; Mon, 26 Nov 2007 10:33:18 +0100 (CET) Received: from imp7-g19.free.fr (imp7-g19.free.fr [212.27.42.38]) by smtp8-g19.free.fr (Postfix) with ESMTP id 0B30917F531; Mon, 26 Nov 2007 10:33:18 +0100 (CET) Received: by imp7-g19.free.fr (Postfix, from userid 33) id 668B13F61; Mon, 26 Nov 2007 10:27:23 +0100 (CET) Received: from 145.242.11.1 ([145.242.11.1]) by imp.free.fr (IMP) with HTTP for ; Mon, 26 Nov 2007 10:27:23 +0100 Message-ID: <1196069243.474a917b04d95@imp.free.fr> Date: Mon, 26 Nov 2007 10:27:23 +0100 From: gregoryd.freebsd@free.fr To: Robert Watson References: <474830F9.90305@zirakzigil.org> <6eb82e0711240638g2cc1e54o1fb1321cafe8ff9f@mail.gmail.com> <1188.202.127.99.4.1195957922.squirrel@webmail.triplegate.net.id> <20071125110116.U63238@fledge.watson.org> <7bc80d500711251205w1a74b649mc3bd374545c1012c@mail.gmail.com> <7bc80d500711251209p3bd78bc0leb37d4cb85f677f3@mail.gmail.com> <20071125203321.G65286@fledge.watson.org> In-Reply-To: <20071125203321.G65286@fledge.watson.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.2.5 X-Originating-IP: 145.242.11.1 Cc: freebsd-hackers@freebsd.org Subject: Re: Before & After Under The Giant Lock 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, 26 Nov 2007 09:57:40 -0000 Hello, Quoting Robert Watson : > No problem -- just to be clear: in 7, users can still choose between > libpthread (m:n) and libthr (1:1), but the default is now libthr rather than > libpthread, as libthr seemed to perform better in most if not all workloads > of > interest. I thought 1:1 would perform better with I/O bound processes running several threads. But wouldn't a process rely on a few I/O threads for several other CPU bound threads ? (unless specific activities such as a web server, or a database, which would explain MySQL performing better with 1:1) Or, to make my point (somewhat) clearer: how did you actually compare advantages of 1:1 versus M:N when the change from the latter to the former was decided ? And second question: would it be possible to dynamically choose one way over the other: meaning if you know you're mostly I/O bound, then request for the 1:1 type of threads, and vice versa ? thanks, gregory