Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 20 Dec 2001 13:02:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 20 Dec 2001 13:02:47 -0500 Received: from mail.xmailserver.org ([208.129.208.52]:40466 "EHLO mail.xmailserver.org") by vger.kernel.org with ESMTP id ; Thu, 20 Dec 2001 13:02:31 -0500 Date: Thu, 20 Dec 2001 10:05:25 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@blue1.dev.mcafeelabs.com To: Dan Kegel cc: mingo@elte.hu, "David S. Miller" , bcrl , billh , torvalds , linux-kernel , linux-aio Subject: Re: aio In-Reply-To: <3C22129C.4A4E2269@kegel.com> Message-ID: 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 On Thu, 20 Dec 2001, Dan Kegel wrote: > Ingo Molnar wrote: > > > it's not a fair comparison. The system was set up to not exhibit any async > > IO load. So a pure, atomic sendfile() outperformed TUX slightly, where TUX > > did something slightly more complex (and more RFC-conform as well - see > > Date: caching in X12 for example). Not something i'd call a proof - this > > simply works around the async IO interface. (which RT-signal driven, > > fasync-helped async IO interface, as phttpd has proven, is not only hard > > to program and is unrobust, it also performs *very badly*.) > > Proper wrapper code can make them (almost) easy to program with. > See http://www.kegel.com/dkftpbench/doc/Poller_sigio.html for an example > of a wrapper that automatically handles the fallback to poll() on overflow. > Using this wrapper I wrote ftp clients and servers which use a thin wrapper > api that lets the user choose from select, poll, /dev/poll, kqueue/kevent, and RT signals > at runtime. Hey, you forgot /dev/epoll, the fastest one :) - 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/