From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752346AbXCAIXo (ORCPT ); Thu, 1 Mar 2007 03:23:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933014AbXCAIXo (ORCPT ); Thu, 1 Mar 2007 03:23:44 -0500 Received: from relay.2ka.mipt.ru ([194.85.82.65]:53040 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbXCAIXn (ORCPT ); Thu, 1 Mar 2007 03:23:43 -0500 Date: Thu, 1 Mar 2007 11:18:08 +0300 From: Evgeniy Polyakov To: Pavel Machek 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: <20070301081808.GD7217@2ka.mipt.ru> References: <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> <20070228161413.GA4319@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20070228161413.GA4319@ucw.cz> User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (2ka.mipt.ru [0.0.0.0]); Thu, 01 Mar 2007 11:20:08 +0300 (MSK) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 28, 2007 at 04:14:14PM +0000, Pavel Machek (pavel@ucw.cz) wrote: > 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. Should I create a patch to remove rb-tree implementation? That practice is stupid IMO. > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- Evgeniy Polyakov