From owner-freebsd-threads@FreeBSD.ORG Mon Jul 10 09:23:43 2006 Return-Path: X-Original-To: freebsd-threads@freebsd.org Delivered-To: freebsd-threads@freebsd.org Received: from [127.0.0.1] (localhost [127.0.0.1]) by hub.freebsd.org (Postfix) with ESMTP id 1E2FC16A4ED; Mon, 10 Jul 2006 09:23:39 +0000 (UTC) (envelope-from davidxu@freebsd.org) Message-ID: <44B21C9A.3010800@freebsd.org> Date: Mon, 10 Jul 2006 17:23:38 +0800 From: David Xu User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.12) Gecko/20060519 X-Accept-Language: en-us, en MIME-Version: 1.0 To: kmacy@fsmware.com References: <20060703101554.Q26325@fledge.watson.org> <200607042204.52572.davidxu@freebsd.org> <44AAC47F.2040508@elischer.org> <200607041819.05510.peter@wemm.org> <44AB4C22.3030109@elischer.org> <20060705095450.O64340@fledge.watson.org> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Daniel Eischen , threads@freebsd.org, Robert Watson , Julian Elischer , freebsd-threads@freebsd.org Subject: Re: Strawman proposal: making libthr default thread implementation? X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Jul 2006 09:23:43 -0000 Kip Macy wrote: > > Apart from real time scheduling functionality I have yet to see any > real-world technical deficiencies with libthr. I have, however, seen > major stability issues with KSE. > > Network Appliance abandoned FreeBSD as a platform for running their > simulator due to frequent hangs caused by signals. More recently, on > sun4v, when single stepping csup (or any multi-threaded app for that > matter) the debuggee would often get the SIGTRAP and not GDB. When > re-starting mysqld for the second or third time the process would > become unkillable. These problems are not entirely surprising, KSE > makes signal handling *very* complicated. I am disappointed that > threads are currently unusable on sun4v with KSE. > > I would be delighted if sometime in the very near future, one of the > following happened: > 1. > a) Somebody steps up to work on KSE and fixes the signal issues that > have long plagued it. John Birrell or Paul Saab can make a T2000 > available to any motivated developer. > > 2. > a) David Xu fixes static linking with libthr I really want somebody who is familiar with weak symbol to help me, since both libthr and libc are using weak symbols (our ABI), according to what my fellows here said, weak symbols are picked up by linker randomly, so how to fix it? I had dicussed this issue with dan, but never got a satisfied answer. > b) David Xu exports support for real-time scheduling via libthr This can be implemented in short time. > c) Peter Wemm checks in bike_sched > > The second seems much more logical, given our desire to become > performance competitive with Linux. However, sched_lock is not > currently FreeBSD's biggest bottleneck, and thus the first would be > acceptable. I would still be pleased at the possibility of sun4v > someday being checked into CVS. > I don't have objection. :-) > -Kip David Xu