From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Make TCP work better with re-ordered frames? Date: Wed, 18 May 2016 07:00:46 -0700 Message-ID: <573C758E.9050008@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: "netdev@vger.kernel.org" Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:55143 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752494AbcEROAs (ORCPT ); Wed, 18 May 2016 10:00:48 -0400 Received: from [50.34.199.106] (unknown [50.34.199.106]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail2.candelatech.com (Postfix) with ESMTPSA id 77B6540A79A for ; Wed, 18 May 2016 07:00:47 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: We are investigating a system that has fairly poor TCP throughput with the 3.17 and 4.0 kernels, but evidently it worked pretty well with 3.14 (I should be able to verify 3.14 later today). One thing I notice is that a UDP download test shows lots of reordered frames, so I am thinking maybe TCP is running slow because of this. (We see about 800Mbps UDP download, but only 500Mbps TCP, even when using 100 concurrent TCP streams.) Is there some way to tune the TCP stack to better handle reordered frames? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com