From owner-freebsd-net@FreeBSD.ORG Thu Jul 3 02:09:15 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 7C5795FB for ; Thu, 3 Jul 2014 02:09:15 +0000 (UTC) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 43FC42CB5 for ; Thu, 3 Jul 2014 02:09:14 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgQFACq5tFODaFve/2dsb2JhbABag19agm+oUAECAQEBBpMUhm5TAYEgdYQDAQEBAwEBAQEgBCcgCwUWGAICDRkCKQEJJgYIBwQBGQMEiBkIDatUm3MXgSyERIhaAQYBARs0B4J3gUwFmAKEM5JCg18hNXwBCBci X-IronPort-AV: E=Sophos;i="5.01,592,1400040000"; d="scan'208";a="137299358" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-jnhn.mail.uoguelph.ca with ESMTP; 02 Jul 2014 22:09:13 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id A1A3AB4069; Wed, 2 Jul 2014 22:09:13 -0400 (EDT) Date: Wed, 2 Jul 2014 22:09:13 -0400 (EDT) From: Rick Macklem To: "Russell L. Carter" Message-ID: <509953671.6648047.1404353353654.JavaMail.root@uoguelph.ca> In-Reply-To: <53B4A605.8000604@pinyon.org> Subject: Re: NFS client READ performance on -current MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.203] X-Mailer: Zimbra 7.2.6_GA_2926 (ZimbraWebClient - FF3.0 (Win)/7.2.6_GA_2926) Cc: freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Jul 2014 02:09:15 -0000 Russell L. Carter wrote: > > > On 07/02/14 17:17, Michael Sierchio wrote: > > sysctl net.inet.tcp.tso=0 > > Woot! 2.7MB/s -> 76MB/s > > Is this a FAQ somewhere? I spent a long time looking > today and didn't find it (I do recall seeing a mention > of TSO but not seeing how to do it or that it fixed > the problem) > Unfortunately, this isn't good news for me. I had thought the worst of the TSO related problems had been resolved in head. The one I knew about was a case where a read/write just under 64K would result in a TSO segment (including ethernet header) just over 64K (which can't fit in 32 mbuf clusters, while 32 is the limit for transmit segments for some TSO enabled interfaces). I think this is fixed in head by r264630, which reduces the maximum tso segment length by a small amount. Admittedly, if the network interface is limited to less than 35 transmit segments and does not use m_defrag() to compact the TSO segment into 32mbuf clusters, it would still be broken. The m_defrag() calls will result in overhead, but I don't think they would cause that much effect. Could you please post the dmesg stuff for the network interface, so I can tell what driver is being used? I'll take a look at it, in case it needs to be changed to use m_defrag(). Thanks for letting us know this fixed the problem, rick > On the second suggestion: > > root@feyerabend> sysctl -a | grep dev.em | grep enable_ > root@feyerabend> > > No problem, though. 76MB/s is A-OK. > > Thanks! I'm very happy now. > > Russell > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to > "freebsd-net-unsubscribe@freebsd.org" >