From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Holt Subject: Re: Zero copy transmit Date: Tue, 29 Apr 2003 14:33:36 -0500 Sender: netdev-bounce@oss.sgi.com Message-ID: <20030429193336.GA32270@sgi.com> References: <3EAEC7FF.4040504@sgi.com> <20030429192041.GC17413@Wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Steve Modica , netdev@oss.sgi.com Return-path: To: Andi Kleen Content-Disposition: inline In-Reply-To: <20030429192041.GC17413@Wotan.suse.de> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Tue, Apr 29, 2003 at 09:20:41PM +0200, Andi Kleen wrote: > A much better way would be to use the POSIX aio interfaces. They support > zero copy transmit, but don't require COW. Instead they just tell > the user process when it is safe to touch the buffer again. > > There was already some code to do aio TCP sending, but it didn't > do zero copy and was not merged for some reason. > > Also you can already do zero copy transmit using sendfile() Users would need to rewrite all their apps to use either the async or sendfile method. That assumption seems a little broad. I don't disagree that implementing the remainder of the AIO system calls would also be good, but is there something wrong with getting write et. al. to work with zero copy? Robin Holt