From owner-freebsd-xen@FreeBSD.ORG Fri Jun 7 20:27:09 2013 Return-Path: Delivered-To: freebsd-xen@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id A7917F33; Fri, 7 Jun 2013 20:27:09 +0000 (UTC) (envelope-from mcdouga9@egr.msu.edu) Received: from mail.egr.msu.edu (boomhauer.egr.msu.edu [35.9.37.167]) by mx1.freebsd.org (Postfix) with ESMTP id 0EE8112ED; Fri, 7 Jun 2013 20:27:09 +0000 (UTC) Received: from boomhauer (localhost [127.0.0.1]) by mail.egr.msu.edu (Postfix) with ESMTP id D761634360; Fri, 7 Jun 2013 16:27:07 -0400 (EDT) X-Virus-Scanned: amavisd-new at egr.msu.edu Received: from mail.egr.msu.edu ([127.0.0.1]) by boomhauer (boomhauer.egr.msu.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RXcRHTm4KqNx; Fri, 7 Jun 2013 16:27:07 -0400 (EDT) Received: from daemon.localdomain (daemon.egr.msu.edu [35.9.44.65]) by mail.egr.msu.edu (Postfix) with ESMTP id B31E13435A; Fri, 7 Jun 2013 16:27:07 -0400 (EDT) Received: by daemon.localdomain (Postfix, from userid 21281) id ACF5E11AF59; Fri, 7 Jun 2013 16:27:07 -0400 (EDT) Date: Fri, 7 Jun 2013 16:27:07 -0400 From: Adam McDougall To: Colin Percival Subject: Re: svn commit: r251297 - head/sys/dev/xen/netfront Message-ID: <20130607202707.GB4240@egr.msu.edu> References: <201306031300.r53D0XUx092178@svn.freebsd.org> <51AD0571.90007@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51AD0571.90007@freebsd.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-xen@FreeBSD.org X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Jun 2013 20:27:09 -0000 On Mon, Jun 03, 2013 at 02:06:57PM -0700, Colin Percival wrote: On 06/03/13 06:00, Andre Oppermann wrote: > Log: > Specify a maximum TSO length limiting the segment chain to what the > Xen host side can handle after defragmentation. > > This prevents the driver from throwing away too long TSO chains and > improves the performance on Amazon AWS instances with 10GigE virtual > interfaces to the normally expected throughput. Thanks! For the benefit of the list: This (and the r251296, which provides the network stack infrastructure which this commit uses) was the last of the "make FreeBSD behave well in Amazon EC2" patches I've been carrying around (and building into my EC2 images) for the past two years. Now the only step remaining to make FreeBSD/EC2 pure "straight off the RELEASE ISO" FreeBSD is to get Xen HVM functionality into GENERIC. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid Is it possible to turn it into a boot time tunable in case XENHVM puts a system at a disadvantage? I'm specifically thinking of some XENHVM environments under XenServer and related products that aren't currently compat with having a virtual cdrom due to a bug. Removing the virtual cdrom drive is a workaround but that makes it a lot harder to boot from a RELEASE ISO :) Apologies if it already has a tunable, but I did some searching and could not locate it. It was desirable too back when a XENHVM kernel would panic on bare hw but that was fixed a while ago.