From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larry McVoy Subject: Re: TCP IP Offloading Interface Date: Sun, 13 Jul 2003 16:54:24 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <20030713235424.GB31793@work.bitmover.com> References: <20030713004818.4f1895be.davem@redhat.com> <52u19qwg53.fsf@topspin.com> <20030713160200.571716cf.davem@redhat.com> <20030713233503.GA31793@work.bitmover.com> <20030713164003.21839eb4.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Larry McVoy , roland@topspin.com, alan@storlinksemi.com, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org, netdev@oss.sgi.com Return-path: To: "David S. Miller" Content-Disposition: inline In-Reply-To: <20030713164003.21839eb4.davem@redhat.com> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org > The whole point is to not touch any of this data. > > The idea is to push the pages directly into the page cache > of the filesystem. It doesn't work. Measure the cost of the VM operations before you go down this path. Just set up a system call that swaps a page with a kernel allocated buffer and then see how many of those you can do a second. Maybe Linux is so blindingly fast this makes sense but IRIX certainly wasn't, the VM overhead hurt like crazy. Every time I tried to push the page flip idea or offloading or any of that crap, Andy Bechtolsheim would tell "the CPUs will get faster faster than you can make that work". He was right. -- --- Larry McVoy lm at bitmover.com http://www.bitmover.com/lm