From owner-freebsd-net@FreeBSD.ORG  Tue Dec 21 07:32:25 2010
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3218E10656A5
	for <net@freebsd.org>; Tue, 21 Dec 2010 07:32:25 +0000 (UTC)
	(envelope-from egrosbein@rdtc.ru)
Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [62.231.161.221])
	by mx1.freebsd.org (Postfix) with ESMTP id 9173D8FC2A
	for <net@freebsd.org>; Tue, 21 Dec 2010 07:32:24 +0000 (UTC)
Received: from eg.sd.rdtc.ru (localhost [127.0.0.1])
	by eg.sd.rdtc.ru (8.14.4/8.14.4) with ESMTP id oBL7WLBc029819;
	Tue, 21 Dec 2010 13:32:21 +0600 (NOVT)
	(envelope-from egrosbein@rdtc.ru)
Message-ID: <4D105800.2070808@rdtc.ru>
Date: Tue, 21 Dec 2010 13:32:16 +0600
From: Eugene Grosbein <egrosbein@rdtc.ru>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; ru-RU;
	rv:1.9.1.10) Gecko/20100712 Thunderbird/3.0.5
MIME-Version: 1.0
To: Shtorm <admin@shtorm.com>
References: <4D0CFEFF.3000902@rdtc.ru> <1292844095.1917.136.camel@stormi>
In-Reply-To: <1292844095.1917.136.camel@stormi>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: net@freebsd.org
Subject: Re: lagg/lacp poor traffic distribution
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 21 Dec 2010 07:32:25 -0000

On 20.12.2010 17:21, Shtorm wrote:

> I had this problem with igb driver, and I found, that lagg selects
> outgoing interface based on packet header flowid field if M_FLOWID field
> is set. And in the igb driver code flowid is set as 
> 
> #if __FreeBSD_version >= 800000
> <------><------><------>rxr->fmp->m_pkthdr.flowid = que->msix;
> <------><------><------>rxr->fmp->m_flags |= M_FLOWID;
> #endif
> 
> The same thing in em driver with MULTIQUEUE 
> 
> That does not give enough number of flows to balance traffic well, so I
> commented check in if_lagg.c
> 
> lagg_lb_start(struct lagg_softc *sc, struct mbuf *m)
> {
> <------>struct lagg_lb *lb = (struct lagg_lb *)sc->sc_psc;
> <------>struct lagg_port *lp = NULL;
> <------>uint32_t p = 0;
> 
> //<---->if (m->m_flags & M_FLOWID)
> //<----><------>p = m->m_pkthdr.flowid;
> //<---->else
> 
> and with this change I have much better load distribution across interfaces.
> 
> Hope it helps.
> 

I've made new sysctl net.link.lagg.use_flows to enable/disable
this code in run time and disabled it. No change.

--- if_lagg.c.orig	2010-12-20 22:53:21.000000000 +0600
+++ if_lagg.c	2010-12-20 22:57:50.000000000 +0600
@@ -168,6 +168,11 @@
     &lagg_failover_rx_all, 0,
     "Accept input from any interface in a failover lagg");
 
+static int lagg_use_flows = 1;
+SYSCTL_INT(_net_link_lagg, OID_AUTO, use_flows, CTLFLAG_RW,
+    &lagg_use_flows, 1,
+    "Use flows for load sharing");
+
 static int
 lagg_modevent(module_t mod, int type, void *data)
 {
@@ -1666,7 +1671,7 @@
 	struct lagg_port *lp = NULL;
 	uint32_t p = 0;
 
-	if (m->m_flags & M_FLOWID)
+	if (lagg_use_flows && (m->m_flags & M_FLOWID))
 		p = m->m_pkthdr.flowid;
 	else
 		p = lagg_hashmbuf(m, lb->lb_key);