Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752760AbXE3IgK (ORCPT ); Wed, 30 May 2007 04:36:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751646AbXE3Ifu (ORCPT ); Wed, 30 May 2007 04:35:50 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:41855 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751470AbXE3Ifs (ORCPT ); Wed, 30 May 2007 04:35:48 -0400 Date: Wed, 30 May 2007 12:32:54 +0400 From: Evgeniy Polyakov To: Ingo Molnar Cc: Jeff Garzik , Zach Brown , linux-kernel@vger.kernel.org, Linus Torvalds , Arjan van de Ven , Christoph Hellwig , Andrew Morton , Alan Cox , Ulrich Drepper , "David S. Miller" , Suparna Bhattacharya , Davide Libenzi , Jens Axboe , Thomas Gleixner Subject: Re: Syslets, Threadlets, generic AIO support, v6 Message-ID: <20070530083254.GA21528@2ka.mipt.ru> References: <20070529212718.GH7875@mami.zabbo.net> <465CA654.5000505@garzik.org> <20070530072055.GA3077@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20070530072055.GA3077@elte.hu> 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]); Wed, 30 May 2007 12:33:21 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2484 Lines: 57 Hi Ingo, developers. On Wed, May 30, 2007 at 09:20:55AM +0200, Ingo Molnar (mingo@elte.hu) wrote: > > * Jeff Garzik wrote: > > > You should pick up the kevent work :) > > 3 months ago i verified the published kevent vs. epoll benchmark and > found that benchmark to be fatally flawed. When i redid it properly > kevent showed no significant advantage over epoll. Note that i did those > measurements _before_ the recent round of epoll speedups. So unless > someone does believable benchmarks i consider kevent an over-hyped, > mis-benchmarked complication to do something that epoll is perfectly > capable of doing. I did not want to start with another round of ping-pong insults :), but, Ingo, you did not show that kevent works worse. I did show that sometimes it works better. It flawed from 0 to 30% win in that tests, in results Johann Bork presented kevent and epoll behaved the same. In results I posted earlier, I said, that sometimes epoll behaved better, sometimes kevent. What does it say? Just the fact, that in that given workload result was the one we saw. Nothing more, nothing less. It does not show something is broken, and definitely not that it is: citation1: we're heading to yet-another monolitic interface, we're heading with no valid reasons given if other than some handwaving. citation2: consider kevent an over-hyped, mis-benchmarked complication to do something that epoll is perfectly Getting into account another features kevent has (and what it was designed for originally - for network AIO, which is quite hard (if ever possible) with files and epoll, I'm not talking about syslets as AIO, it is different approach and likely it is simpler, getting even only that it is already very good), it is not what people said in above citations. It looks like you have some personal insults on that, which I do not understand. But it has nothing with technical side of the problem, so lets stop such rethoric and concentrate on real problem and forget any possible personal issues which might be raised sometimes :). Although I closed kevent and eventfs projects, I would gladly continue if we can and want to have progress in that area. Thanks. > Ingo -- Evgeniy Polyakov - 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/