From owner-freebsd-hackers@FreeBSD.ORG Sun Nov 25 20:29:42 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 2F40516A41B for ; Sun, 25 Nov 2007 20:29:42 +0000 (UTC) (envelope-from muffaleta@gmail.com) Received: from mu-out-0910.google.com (mu-out-0910.google.com [209.85.134.184]) by mx1.freebsd.org (Postfix) with ESMTP id AEF0613C465 for ; Sun, 25 Nov 2007 20:29:41 +0000 (UTC) (envelope-from muffaleta@gmail.com) Received: by mu-out-0910.google.com with SMTP id i10so645499mue for ; Sun, 25 Nov 2007 12:29:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=eOiSZzX1Q2a6cCKBdQdmaKJEbcXIqV6ANGLDJmBrwuA=; b=IIJ9Eiqyx0D/z84/+BcyawJEi5YBWX0Vv+Ftg2j+X7Fw7pXw4TUhHwQbdFj8Fg1hSX61WcpgmHDqkRwhOqMHFvAf80hFsytmywNmTBUsqRUe8t0JzMN0cyQsiSPjOtJHb7iRkJxC3yJ7KXLSH90XyRFdfEJ83uDwshplIp/z4uk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Z5lHgX8xk35LEuAv9EQtR0KJfY11i0iin0Gs7TuEdy5WImKTK/l0tmtxoJVNF6aLOShiNIa6NdlrZCLMbBtiInustlZJUbo5eMZgnY/Qe3gERgvj3URip09DKumBkAxsM9pTKGJTfD3nzxpBiMHVcQXt63t8Jtifij3RVMuc8Jc= Received: by 10.82.138.6 with SMTP id l6mr5171051bud.1196021129953; Sun, 25 Nov 2007 12:05:29 -0800 (PST) Received: by 10.82.108.11 with HTTP; Sun, 25 Nov 2007 12:05:29 -0800 (PST) Message-ID: <7bc80d500711251205w1a74b649mc3bd374545c1012c@mail.gmail.com> Date: Sun, 25 Nov 2007 12:05:29 -0800 From: "Christopher Chen" To: "Robert Watson" In-Reply-To: <20071125110116.U63238@fledge.watson.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline 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> 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: Sun, 25 Nov 2007 20:29:42 -0000 On Nov 25, 2007 3:13 AM, Robert Watson wrote: > At this point, Giant is gradually becoming a lock around the tty, newbus, usb, > and msdosfs code, and we're largely at diminishing returns in terms of making > improvements in parallelism through removing Giant. In FreeBSD 7, the focus > was on improving parallelism rather than removing Giant, with improvements in > locking primitives, the scheduler, and lock granularity. For example, most of > the improvement in MySQL performance in FreeBSD 7 can be put down to a small > number of changes: > > - Conversion to 1:1 threads from M:N threads. Dear Robert: I enjoyed reading your overview of changes from FreeBSD 6 to 7 with regards to MP scalability, but I am a bit confused over this point--Doesn't the user still have the choice between libthread, which is M:N, and libthr, which is 1:1? At some point during the 6.x days, it was considered advantageous to use libthr when running MySQL. Has the project decided to go with libthread after all? Perhaps we're talking about entirely different things. Cheers, Chris -- Chris Chen "I want the kind of six pack you can't drink." -- Micah