Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751795AbXBVTqu (ORCPT ); Thu, 22 Feb 2007 14:46:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751801AbXBVTqu (ORCPT ); Thu, 22 Feb 2007 14:46:50 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:4733 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751795AbXBVTqu (ORCPT ); Thu, 22 Feb 2007 14:46:50 -0500 X-AuthUser: davidel@xmailserver.org Date: Thu, 22 Feb 2007 11:46:48 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Evgeniy Polyakov cc: Ingo Molnar , Ulrich Drepper , Linux Kernel Mailing List , Linus Torvalds , Arjan van de Ven , Christoph Hellwig , Andrew Morton , Alan Cox , Zach Brown , "David S. Miller" , Suparna Bhattacharya , Jens Axboe , Thomas Gleixner Subject: Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3 In-Reply-To: <20070222133201.GB5208@2ka.mipt.ru> Message-ID: References: <20070221211355.GA7302@elte.hu> <20070221233111.GB5895@elte.hu> <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> <20070222113148.GA3781@2ka.mipt.ru> <20070222125931.GB25788@elte.hu> <20070222133201.GB5208@2ka.mipt.ru> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1585 Lines: 35 On Thu, 22 Feb 2007, Evgeniy Polyakov wrote: > > maybe it will, maybe it wont. Lets try? There is no true difference > > between having a 'request structure' that represents the current state > > of the HTTP connection plus a statemachine that moves that request > > between various queues, and a 'kernel stack' that goes in and out of > > runnable state and carries its processing state in its stack - other > > than the amount of RAM they take. (the kernel stack is 4K at a minimum - > > so with a million outstanding requests they would use up 4 GB of RAM. > > With 20k outstanding requests it's 80 MB of RAM - that's acceptable.) > > I tried already :) - I just made a allocations atomic in tcp_sendmsg() and > ended up with 1/4 of the sends blocking (I counted both allocation > failure and socket queue overflow). Those 20k blocked requests were > created in about 20 seconds, so roughly saying we have 1k of thread > creation/freeing per second - do we want this? A dynamic pool will smooth thread creation/freeing up by a lot. And, in my box a *pthread* create/free takes ~10us, at 1000/s is 10ms, 1%. Bad, but not so aweful ;) Look, I'm *definitely* not trying to advocate the use of async syscalls for network here, just pointing out that when we're talking about threads, Linux does a pretty good job. - Davide - 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/