From owner-freebsd-net@FreeBSD.ORG Mon Jun 1 14:53:52 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2BB799F for ; Mon, 1 Jun 2015 14:53:52 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-ie0-x22e.google.com (mail-ie0-x22e.google.com [IPv6:2607:f8b0:4001:c03::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E94D61B5D for ; Mon, 1 Jun 2015 14:53:51 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by ieclw1 with SMTP id lw1so15582551iec.3 for ; Mon, 01 Jun 2015 07:53:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=8CsagijCO+4vBHWHk/vToYjOs5rgxavLj7acN+XEUQM=; b=SS6ZmmpIMyHNhMhBaygyewHO+9cfyQoCIvQImLx57DQOj3KTZSYCT/gV1yX8fxWoZ4 o9YB+DSl9s2eszSfDvk/En1PFQZCXwq4KUomch/fVVFvZgIis0mTRUjNl/YHogZt8n09 UueqszUzcVfZtif/sJJCPePhdKKspYH9NaWU2f8OR14KXAiCJZEH/Ke6WY5iAQsxJDf3 xpTK5ezWZgZfO6J2cEdrsQm+KWJFwVsBlk4KUCW0+D5JvKjUrD2d9XFWVKo3Zg3JFqWm 9Ent/vQC4jey7ng3bP+ir51mk3m3vTNWUiokxWpPoFfs9tHW8e/UGsB/HatD+wCodYYH iMug== MIME-Version: 1.0 X-Received: by 10.107.11.26 with SMTP id v26mr3799359ioi.8.1433170431404; Mon, 01 Jun 2015 07:53:51 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.38.133 with HTTP; Mon, 1 Jun 2015 07:53:51 -0700 (PDT) In-Reply-To: References: <20150601082509.GE1647@zxy.spb.ru> Date: Mon, 1 Jun 2015 07:53:51 -0700 X-Google-Sender-Auth: -TI7-DrfjNMuEOqAx54_k4sl1_I Message-ID: Subject: Re: Intel igb 82576 (netmap mode) and RSS queue issuse with fragmented UDP packets. From: Adrian Chadd To: Slawa Olhovchenkov Cc: FreeBSD Net Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Jun 2015 14:53:52 -0000 oh, hm, you asked the next question. Sorry, I haven't had coffee. I vaguely remember testing this and discovering the /should/ be putting all the frames in a packet int he same queue, as long as the frames have a consistent set of fragment bits set. Ie, if you're doing UDP and all frames in a packet have the fragment bit set, then all fragments (first and the rest) go into the same queue. Frames in a flow that are fragmented for some and not others (eg TCP flows with a firewall/router doing explicit fragmentation, or a mix of small/large UDP packets) will end up going into different queues. I can re-test this on ixgbe at some point, but IIRC that's how it behaved. I don't have the RSS stuff done for chelsio, so I haven't done any experiments just yet. Now, I also remember that with the badly setup flowdirector code in ixgbe it would mess that up, so the flowdir code was disabled in -HEAD and I believe now in -10. -adrian