Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964899AbXBLMIm (ORCPT ); Mon, 12 Feb 2007 07:08:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964893AbXBLMIm (ORCPT ); Mon, 12 Feb 2007 07:08:42 -0500 Received: from ns2.suse.de ([195.135.220.15]:35749 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964891AbXBLMIl (ORCPT ); Mon, 12 Feb 2007 07:08:41 -0500 To: Evgeniy Polyakov Cc: David Miller , Ulrich Drepper , Andrew Morton , netdev , Zach Brown , Christoph Hellwig , Chase Venters , Johann Borck , linux-kernel@vger.kernel.org, Jeff Garzik , Jamal Hadi Salim , Ingo Molnar , linux-fsdevel@vger.kernel.org Subject: Re: [take36 10/10] kevent: Kevent based generic AIO. References: <11712796493850@2ka.mipt.ru> <1171279650540@2ka.mipt.ru> From: Andi Kleen Date: 12 Feb 2007 14:08:10 +0100 In-Reply-To: <1171279650540@2ka.mipt.ru> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 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: 1204 Lines: 19 Evgeniy Polyakov writes: > > aio_sendfile_path() is essentially aio_sendfile(), except that it takes > source filename as parameter, has a pointer to private header > and its size (which allows to send header and file's content in one syscall > instead of three (open, send, sendfile) and returns opened file descriptor. Are you sure this is a useful optimization? Do you have numbers vs open+aio_sendfile+close? Compared to the cost of sending a complete file three system calls should be quite in the noise. And Linux system calls are not that expensive (few hundred cycles normally) Adding such compound system calls would be a worrying precedent because I'm sure others would want them then for their favourite system call combo too. If they were really useful it might make more sense to have a batch() system call that works for arbitary calls, but I'm not convinced yet it's even needed. It would be certainly ugly. -Andi - 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/