From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 27 Jan 2001 01:20:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 27 Jan 2001 01:20:17 -0500 Received: from vitelus.com ([64.81.36.147]:11788 "EHLO vitelus.com") by vger.kernel.org with ESMTP id ; Sat, 27 Jan 2001 01:20:11 -0500 Date: Fri, 26 Jan 2001 22:20:03 -0800 From: Aaron Lehmann To: Andrew Morton Cc: lkml , "netdev@oss.sgi.com" Subject: Re: sendfile+zerocopy: fairly sexy (nothing to do with ECN) Message-ID: <20010126222003.A11994@vitelus.com> In-Reply-To: <3A726087.764CC02E@uow.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i In-Reply-To: <3A726087.764CC02E@uow.edu.au>; from andrewm@uow.edu.au on Sat, Jan 27, 2001 at 04:45:43PM +1100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 27, 2001 at 04:45:43PM +1100, Andrew Morton wrote: > 2.4.1-pre10-vanilla, using read()/write(): 34.5% CPU > 2.4.1-pre10+zercopy, using read()/write(): 38.1% CPU Am I right to be bothered by this? The majority of Unix network traffic is handled with read()/write(). Why would zerocopy slow that down? If zerocopy is simply unoptimized, that's fine for now. But if the problem is inherent in the implementation or design, that might be a problem. Any patch which incurs a signifigant slowdown on traditional networking should be contraversial. Aaron Lehmann please ignore me if I don't know what I'm talking about. - 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/