From owner-freebsd-virtualization@FreeBSD.ORG Sat Nov 22 10:24:53 2008 Return-Path: Delivered-To: freebsd-virtualization@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1CF271065674 for ; Sat, 22 Nov 2008 10:24:53 +0000 (UTC) (envelope-from julian@elischer.org) Received: from outC.internet-mail-service.net (outc.internet-mail-service.net [216.240.47.226]) by mx1.freebsd.org (Postfix) with ESMTP id F0F2A8FC12 for ; Sat, 22 Nov 2008 10:24:52 +0000 (UTC) (envelope-from julian@elischer.org) Received: from idiom.com (mx0.idiom.com [216.240.32.160]) by out.internet-mail-service.net (Postfix) with ESMTP id 1354F23F9; Sat, 22 Nov 2008 02:12:06 -0800 (PST) X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e Received: from julian-mac.elischer.org (home.elischer.org [216.240.48.38]) by idiom.com (Postfix) with ESMTP id 8B1DA2D6004; Sat, 22 Nov 2008 02:12:02 -0800 (PST) Message-ID: <4927DAF2.5040709@elischer.org> Date: Sat, 22 Nov 2008 02:12:02 -0800 From: Julian Elischer User-Agent: Thunderbird 2.0.0.18 (Macintosh/20081105) MIME-Version: 1.0 To: Jason Fines References: <5e6025b70811212019h64feb7dcrd02ab78ba1b558c3@mail.gmail.com> In-Reply-To: <5e6025b70811212019h64feb7dcrd02ab78ba1b558c3@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-virtualization@freebsd.org Subject: Re: Question About TCP Reassembly Inside VImages X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Nov 2008 10:24:53 -0000 Jason Fines wrote: > Hello all, > > I've got a question about setting the sysctl variable > net.inet.tcp.reass.maxsegments to a non-zero value inside my vimages. I'm > currently running the FreeBSD 7 with the VIMAGE package available at > http://imunes.tel.fer.hr/virtnet/vimage_7-20081015.tgz. > > My problem is with TCP reassembly support inside of the vimages, namely with > the tcp.reass.maxsegments sysctl variable. I've tracked down where in the > code the variable is set to line 122 in tcp_reass_init() of > netinet/tcp_reass.c: "V_tcp_reass_maxseg = nmbclusters / 16;". The line > clearly reads that maxsegments should be set to "nmbclusters /16", in the > main OS (not in any vimage) the value is correctly set to 1/16 of what my > nmbclusters sysctl variable is set to. However, inside all my vimages > nmbclusters is set correctly, while reass.maxsegments is incorrectly set to > zero!!! V_tcp_reass_maxseg is a macro that hides the fact that tcp_reass_maxseg is a PER Vimage variable. Part of the patch is to make some sysctls be per-vimage. I do not know exactly about that one.. I suspect it is actually a read-only whole-system value, and not per vimage. > > Is it possible that nmbclusters when read on line 122 of netinet/tcp_reass.c > is zero? Has anyone else experienced this problem? Is TCP reassembly not > supported/tested inside vimages? > > Any help in this area would be greatly appreciated. > > Thanks, > Jason > > P.S. This technology is phenomenal, and thanks to everyone who is involved > developing it. > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to "freebsd-virtualization-unsubscribe@freebsd.org"