Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757192AbXHSWdw (ORCPT ); Sun, 19 Aug 2007 18:33:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756808AbXHSWdk (ORCPT ); Sun, 19 Aug 2007 18:33:40 -0400 Received: from mx1.suse.de ([195.135.220.2]:50517 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751536AbXHSWdj (ORCPT ); Sun, 19 Aug 2007 18:33:39 -0400 To: "Felix Marti" Cc: "David Miller" , jeff@garzik.org, netdev@vger.kernel.org, rdreier@cisco.com, linux-kernel@vger.kernel.org, general@lists.openfabrics.org Subject: Re: [ofa-general] Re: [PATCH RFC] RDMA/CMA: Allocate PS_TCPportsfrom the host TCP port space. References: <000001c7e22e$b7b90f00$29c8180a@amr.corp.intel.com> <20070819.002337.06589160.davem@davemloft.net> <8A71B368A89016469F72CD08050AD334018E208F@maui.asicdesigners.com> <20070819.123212.13769462.davem@davemloft.net> <8A71B368A89016469F72CD08050AD334018E209C@maui.asicdesigners.com> From: Andi Kleen Date: 20 Aug 2007 01:27:35 +0200 In-Reply-To: <8A71B368A89016469F72CD08050AD334018E209C@maui.asicdesigners.com> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 990 Lines: 20 "Felix Marti" writes: > what benefits does the TSO infrastructure give the > non-TSO capable devices? It improves performance on software queueing devices between guests and hypervisors. This is a more and more important application these days. Even when the system running the Hypervisor has a non TSO capable device in the end it'll still save CPU cycles this way. Right now virtualized IO tends to much more CPU intensive than direct IO so any help it can get is beneficial. It also makes loopback faster, although given that's probably not that useful. And a lot of the "TSO infrastructure" was needed for zero copy TX anyways, which benefits most reasonable modern NICs (anything with hardware checksumming) -Andi - 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/