From owner-freebsd-arch@FreeBSD.ORG Thu Apr 3 12:44:37 2003 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8AC3C37B404 for ; Thu, 3 Apr 2003 12:44:37 -0800 (PST) Received: from canning.wemm.org (canning.wemm.org [192.203.228.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id 396CC43FBF for ; Thu, 3 Apr 2003 12:44:37 -0800 (PST) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by canning.wemm.org (Postfix) with ESMTP id 22D902A8A5; Thu, 3 Apr 2003 12:44:37 -0800 (PST) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Terry Lambert In-Reply-To: <3E8C437F.2C81306D@mindspring.com> Date: Thu, 03 Apr 2003 12:44:37 -0800 From: Peter Wemm Message-Id: <20030403204437.22D902A8A5@canning.wemm.org> cc: freebsd-arch@freebsd.org Subject: Re: libthr and 1:1 threading. X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Apr 2003 20:44:37 -0000 Terry Lambert wrote: > I have to ask: > > Why is it so important to people that the libthr performance > gains be impossible to achieve without use of the 1:1 model, > rather than a modification of libc_r, or avoidance of existing > kernel latencies? Cost vs. Benefit is a big factor. As Jeff has shown, writing a functional 1:1 libthr is significantly easier than M:N or the other alternatives. Easier to write, easier to maintain, easier to understand, easier to debug, and *good enough*. Its all very well for somebody to sit on the sidelines and say what we should be doing, but when it comes down to actually doing it, we're the ones in the hot seat and actually have to write it and maintain it and debug it. kse based threads or async call gates or whatever are almost certainly more efficient at runtime, but we've got to get to the 'running' point first. A mathematical proof is no use to somebody who wants threaded mysql or java or mozilla to work well. Neither is an unstable thread library. At the end of the day working code is what counts, and the more highly ambitious threading systems have to pay the development, debugging and maintenence cost to get there. May the best code win! Cheers, -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5