Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 23 Sep 2002 23:17:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 23 Sep 2002 23:17:33 -0400 Received: from mark.mielke.cc ([216.209.85.42]:34564 "EHLO mark.mielke.cc") by vger.kernel.org with ESMTP id ; Mon, 23 Sep 2002 23:17:32 -0400 Date: Mon, 23 Sep 2002 23:20:17 -0400 From: Mark Mielke To: Bill Huey Cc: Peter W?chtler , Ingo Molnar , Larry McVoy , Bill Davidsen , linux-kernel@vger.kernel.org Subject: Re: [ANNOUNCE] Native POSIX Thread Library 0.1 Message-ID: <20020923232017.A2880@mark.mielke.cc> References: <3D8F82E5.90A64E8@mac.com> <20020923184423.B26887@mark.mielke.cc> <20020923230122.GA3642@gnuppy.monkey.org> <20020923191132.D26887@mark.mielke.cc> <20020924002135.GB3797@gnuppy.monkey.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20020924002135.GB3797@gnuppy.monkey.org>; from billh@gnuppy.monkey.org on Mon, Sep 23, 2002 at 05:21:35PM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2686 Lines: 57 On Mon, Sep 23, 2002 at 05:21:35PM -0700, Bill Huey wrote: > ... > The incorrect example where you outline what you think is a M:N call > conversion is (traditional async wrappers instead of upcalls), is something > that don't want to be a future technical strawman that folks create in > this community to attack M:N threading. It may very well still have > legitimacy in the same way that part of the performance of the JVM depends > on accessibilty to a thread's ucontext and run state, which seem to be > initial oversight (unknown reason) when this was originally conceived. > Those are kind of things are what I'm most worried about that eventually > hurt what application folks are on building on top of Linux and its > kernel facilities. > ... > That's the core of my rant and it took quite a while to write up. ;) My part in the rant (really somebody else's rant...) is that if kernel threads can be made to out-perform current implementations of M:N threading, then all that has really been proven is that current M:N practices are not fully optimal. 1:1 in an N:N system is just one face of M:N in an N:N system. A fully functional M:N system _may choose_ to allow M to equal N. Worst possibly cases that I expect to see from people experimenting with this stuff and having a 1:1 system that out-performs commonly available M:N systems: 1) The M:N people innovate, potentially using the new technology made available from the 1:1 people, making a _better_ M:N system 2) The 1:1 system is better, and people use it. As long as they all use a POSIX, or other standard interface, there isn't a problem. If the changes to the kernel made by the 1:1 people are bad, they will be stopped by Linus and many other people, probably including yourself... :-) In any case, I see the 1:1 vs. M:N as a distraction from the *actual* enhancements being designed, which seem to be, support for cheaper kernel threads, something that benefits both parties. mark -- mark@mielke.cc/markm@ncf.ca/markm@nortelnetworks.com __________________________ . . _ ._ . . .__ . . ._. .__ . . . .__ | Neighbourhood Coder |\/| |_| |_| |/ |_ |\/| | |_ | |/ |_ | | | | | | \ | \ |__ . | | .|. |__ |__ | \ |__ | Ottawa, Ontario, Canada One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them... http://mark.mielke.cc/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/