Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1945976AbXBVLhF (ORCPT ); Thu, 22 Feb 2007 06:37:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1945975AbXBVLhF (ORCPT ); Thu, 22 Feb 2007 06:37:05 -0500 Received: from relay.2ka.mipt.ru ([194.85.82.65]:33729 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945976AbXBVLhD (ORCPT ); Thu, 22 Feb 2007 06:37:03 -0500 Date: Thu, 22 Feb 2007 14:31:50 +0300 From: Evgeniy Polyakov To: Ingo Molnar Cc: Ulrich Drepper , linux-kernel@vger.kernel.org, Linus Torvalds , 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: <20070222113148.GA3781@2ka.mipt.ru> References: <20070221211355.GA7302@elte.hu> <20070221233111.GB5895@elte.hu> <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20070222074044.GA4158@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]); Thu, 22 Feb 2007 14:33:11 +0300 (MSK) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1316 Lines: 35 Hi Ingo, developers. On Thu, Feb 22, 2007 at 08:40:44AM +0100, Ingo Molnar (mingo@elte.hu) wrote: > Syslets/threadlets on the other hand, once the core is implemented, have > near zero ongoing maintainance cost (compared to KAIO pushed into every > IO subsystem) and cover all IO disciplines and API variants immediately, > and they are as perfectly asynchronous as it gets. > > So all in one, i used to think that AIO state-machines have a long-term > place within the kernel, but with syslets i think i've proven myself > embarrasingly wrong =B-) Hmm... Try to have a network web server with huge load made on top of syslets/threadlets. It is not a TUX anymore - you had 1024 threads, and all of them will be consumed by tcp_sendmsg() for slow clients - rescheduling will kill a machine. My tests show that with 4k connections per second (8k concurrency) more than 20k connections of 80k total block in tcp_sendmsg() over gigabit lan between quite fast machines. Or threadlet/syslet AIO should not be used with networking too? > 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/