Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751453AbXB1QOf (ORCPT ); Wed, 28 Feb 2007 11:14:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751500AbXB1QOf (ORCPT ); Wed, 28 Feb 2007 11:14:35 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:1418 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751453AbXB1QOe (ORCPT ); Wed, 28 Feb 2007 11:14:34 -0500 Date: Wed, 28 Feb 2007 16:14:14 +0000 From: Pavel Machek To: Evgeniy Polyakov Cc: Theodore Tso , Ingo Molnar , Linus Torvalds , Ulrich Drepper , linux-kernel@vger.kernel.org, Arjan van de Ven , Christoph Hellwig , Andrew Morton , Alan Cox , Zach Brown , "David S. Miller" , Suparna Bhattacharya , Davide Libenzi , Jens Axboe , Thomas Gleixner Subject: Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3 Message-ID: <20070228161413.GA4319@ucw.cz> References: <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> <20070222113148.GA3781@2ka.mipt.ru> <20070226172812.GC22454@2ka.mipt.ru> <20070226195416.GA11188@elte.hu> <20070227102832.GC23170@2ka.mipt.ru> <20070227115221.GJ8154@thunk.org> <20070227121116.GA31597@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070227121116.GA31597@2ka.mipt.ru> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1484 Lines: 32 Hi! > > I think what you are not hearing, and what everyone else is saying > > (INCLUDING Linus), is that for most programmers, state machines are > > much, much harder to program, understand, and debug compared to > > multi-threaded code. You may disagree (were you a MacOS 9 programmer > > in another life?), and it may not even be true for you if you happen > > to be one of those folks more at home with Scheme continuations, for > > example. But it is true that for most kernel programmers, threaded > > programming is much easier to understand, and we need to engineer the > > kernel for what will be maintainable for the majority of the kernel > > development community. > > I understand that - and I totally agree. > But when more complex, more bug-prone code results in higher performance > - that must be used. We have linked lists and binary trees - the latter No-o. Kernel is not designed like that. Often, more complex and slightly faster code exists, and we simply use slower variant, because it is fast enough. 10% gain in speed is NOT worth major complexity increase. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - 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/