From owner-freebsd-hackers Fri Oct 20 16:12:21 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id QAA24594 for hackers-outgoing; Fri, 20 Oct 1995 16:12:21 -0700 Received: from werple.net.au (0@werple.mira.net.au [203.9.190.18]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id QAA24589 for ; Fri, 20 Oct 1995 16:12:16 -0700 Received: from cimaxp1.UUCP (Ucimlogi@localhost) by werple.net.au (8.7/8.7) with UUCP id IAA26825 for hackers@freebsd.org; Sat, 21 Oct 1995 08:41:27 +1000 (EST) Message-Id: <199510202241.IAA26825@werple.net.au> X-Authentication-Warning: werple.net.au: Ucimlogi set sender to cimaxp1!jb using -f Received: by cimaxp1.cimlogic.com.au; (5.65/1.1.8.2/10Sep95-0953AM) id AA18441; Sat, 21 Oct 1995 08:44:09 +1000 From: John Birrell Subject: Re: NetBSD/FreeBSD (pthreads) To: leisner@sdsp.mc.xerox.com (Marty Leisner) Date: Sat, 21 Oct 1995 08:44:09 +1000 (EST) Cc: hackers@freebsd.org, jb@cimlogic.com.au In-Reply-To: <9510201855.AA17636@gnu.mc.xerox.com> from "Marty Leisner" at Oct 20, 95 11:55:04 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-hackers@freebsd.org Precedence: bulk Marty, > > > Why would I want kernel level threads? We try to make do with what's available. I _need_ threads for some applications. I _wanted_ kernel level threads (and I probably still do), but we can be successful with user-space threads. And that's what matters to me. I'm not sure if you want answers to these... > > 1) does a debugger understand userlevel threads? Not to the extent that you can debug individual threads without seeing the other threads. But the debugger is still useful (and not completely useless!). > 2) if I run a threaded application under strace, with kernel > levels threads is may make some sense...with user level threads > there's all this junk in the way... True. It would be nice not to see the 'junk'. > 3) Anyone have good hard numbers about the differences between user/kernel > level threads on performance? No. We don't have a user-space implementation that works on a system with kernel threads. We would have just used the kernel threads (like we do under OSF/1^H^H^H^HDigital UNIX). 8-). > > Like I said, the mit package is awfully clever... > > > > -- > marty > leisner@sdsp.mc.xerox.com > Member of the League for Programming Freedom > > > -- John Birrell CIMlogic Pty Ltd jb@cimlogic.com.au 119 Cecil Street Ph +61 3 9690 9600 South Melbourne Vic 3205 Fax +61 3 9690 6650 Australia Mob +61 18 353 137