Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030724AbWJKA1X (ORCPT ); Tue, 10 Oct 2006 20:27:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030730AbWJKA1X (ORCPT ); Tue, 10 Oct 2006 20:27:23 -0400 Received: from dev.mellanox.co.il ([194.90.237.44]:65153 "EHLO dev.mellanox.co.il") by vger.kernel.org with ESMTP id S1030724AbWJKA1W (ORCPT ); Tue, 10 Oct 2006 20:27:22 -0400 Date: Wed, 11 Oct 2006 02:26:56 +0200 From: "Michael S. Tsirkin" To: Roland Dreier Cc: Stephen Hemminger , Linux Kernel Mailing List , netdev@vger.kernel.org, openib-general@openib.org, Roland Dreier , "David S. Miller" Subject: Re: Dropping NETIF_F_SG since no checksum feature. Message-ID: <20061011002656.GB30093@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1014 Lines: 23 Quoting r. Roland Dreier : > Subject: Re: Dropping NETIF_F_SG since no checksum feature. > > Michael> Maybe I can patch linux to allow SG without checksum? > Michael> Dave, maybe you could drop a hint or two on whether this > Michael> is worthwhile and what are the issues that need > Michael> addressing to make this work? > > What do you really gain by allowing SG without checksum? Someone has > to do the checksum anyway, so I don't see that much difference between > doing it in the networking core before passing the data to/from the > driver, or down in the driver itself. My guess was, an extra pass over data is likely to be expensive - dirtying the cache if nothing else. But I do plan to measure that, and see. -- MST - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/