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 05:38:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 27 Jan 2001 05:38:00 -0500 Received: from horus.its.uow.edu.au ([130.130.68.25]:29418 "EHLO horus.its.uow.edu.au") by vger.kernel.org with ESMTP id ; Sat, 27 Jan 2001 05:37:54 -0500 Message-ID: <3A72A6C9.7D085A39@uow.edu.au> Date: Sat, 27 Jan 2001 21:45:29 +1100 From: Andrew Morton X-Mailer: Mozilla 4.7 [en] (X11; I; Linux 2.4.0-test8 i586) X-Accept-Language: en MIME-Version: 1.0 To: Ion Badulescu CC: lkml , "netdev@oss.sgi.com" , Aaron Lehmann Subject: Re: sendfile+zerocopy: fairly sexy (nothing to do with ECN) In-Reply-To: <3A728475.34CF841@uow.edu.au> <200101271009.f0RA9fb04363@moisil.dev.hydraweb.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ion Badulescu wrote: > > On Sat, 27 Jan 2001 19:19:01 +1100, Andrew Morton wrote: > > > The figures I quoted for the no-hw-checksum case were still > > using scatter/gather. That can be turned off as well and > > it makes it a tiny bit quicker. > > Hmm. Are you sure the differences are not just noise? I don't think so. It's all pretty repeatable. > Unless you > modified the zerocopy patch yourself, it won't use SG without > checksums... I believe it in fact does use SG when hardware tx checksums are unavailable, but this capability wil be removed RSN because userspace can scribble on the pagecache after the checksum has been calculated, and before the frame has hit the wire. - - 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/