From owner-freebsd-hackers Sun Mar 8 21:22:10 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id VAA01272 for freebsd-hackers-outgoing; Sun, 8 Mar 1998 21:22:10 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id VAA01230 for ; Sun, 8 Mar 1998 21:22:02 -0800 (PST) (envelope-from imp@village.org) Received: from pencil-box.village.org [10.0.0.22] by rover.village.org with esmtp (Exim 1.71 #1) id 0yBv0c-0005O4-00; Sun, 8 Mar 1998 22:21:54 -0700 Received: from pencil-box.village.org (localhost [127.0.0.1]) by pencil-box.village.org (8.8.8/8.8.3) with ESMTP id WAA04154; Sun, 8 Mar 1998 22:21:09 -0700 (MST) Message-Id: <199803090521.WAA04154@pencil-box.village.org> To: Marc Slemko Subject: Re: kernel wishlist for web server performance Cc: Julian Elischer , hackers@FreeBSD.ORG In-reply-to: Your message of "Sun, 08 Mar 1998 08:38:38 MST." References: Date: Sun, 08 Mar 1998 22:21:09 -0700 From: "M. Warner Losh" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message Marc Slemko writes: : But the point is that you still have to copy it into the mbuf, you still : have to use the memory for the mbuf, etc. This uses more CPU and memory : bandwidth, increases memory use, and means you may have to chop things up : smaller to avoid using too much memory for mbufs. And how does sendfile() differ from this? It still has to insert protocol headers somehow. : Or, you can use sendfile() and code it so it doesn't have to copy into : mbufs. This is easier because of where the data is coming from. Then don't you lose performance setting up two DMA transfers for the packet? Or do most cards have scatter/gather operations for transmitting packets? Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message