From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 9 Jan 2001 06:29:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 9 Jan 2001 06:29:24 -0500 Received: from ns.caldera.de ([212.34.180.1]:23816 "EHLO ns.caldera.de") by vger.kernel.org with ESMTP id ; Tue, 9 Jan 2001 06:29:09 -0500 Date: Tue, 9 Jan 2001 12:28:10 +0100 From: Christoph Hellwig To: "David S. Miller" Cc: mingo@elte.hu, riel@conectiva.com.br, netdev@oss.sgi.com, linux-kernel@vger.kernel.org Subject: Re: [PLEASE-TESTME] Zerocopy networking patch, 2.4.0-1 Message-ID: <20010109122810.A3115@caldera.de> Mail-Followup-To: "David S. Miller" , mingo@elte.hu, riel@conectiva.com.br, netdev@oss.sgi.com, linux-kernel@vger.kernel.org In-Reply-To: <20010109113145.A28758@caldera.de> <200101091031.CAA01242@pizda.ninka.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <200101091031.CAA01242@pizda.ninka.net>; from davem@redhat.com on Tue, Jan 09, 2001 at 02:31:13AM -0800 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 09, 2001 at 02:31:13AM -0800, David S. Miller wrote: > Date: Tue, 9 Jan 2001 11:31:45 +0100 > From: Christoph Hellwig > > Yuck. A new file_opo just to get a few benchmarks right ... I > hope the writepages stuff will not be merged in Linus tree (but I > wish the code behind it!) > > It's a "I know how to send a page somewhere via this filedescriptor > all by myself" operation. I don't see why people need to take > painkillers over this for 2.4.x. I think f_op->write is stupid, such > a special case file operation just to get a few benchmarks right. > This is the kind of argument I am hearing. > > Orthogonal to f_op->write being for specifying a low-level > implementation of sys_write, f_op->writepage is for specifying a > low-level implementation of sys_sendfile. Can you grok that? Sure. But sendfile is not one of the fundamental UNIX operations... If there was no alternative to this I would probably have not said anything, but with the rw_kiovec file op just before the door I don't see any reason to add this _very_ specific file operation. An alloc_kiovec before and an free_kiovec after the actual call and the memory overhaed of a kiobuf won't hurt so much that it stands against a clean interface, IMHO. > > Linus has already seen this. Originally he had a gripe because in an > older revision of the code used to allow multiple pages to be passed > in an array to the writepage(s) operation. He didn't like that, so I > made it take only one page as he requested. He had no other major > objections to the infrastructure. You get that multiple page call with kiobufs for free... Christoph -- Whip me. Beat me. Make me maintain AIX. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/