From owner-freebsd-net@FreeBSD.ORG  Thu Mar 15 23:41:27 2012
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 654AA1065674;
	Thu, 15 Mar 2012 23:41:27 +0000 (UTC)
	(envelope-from seanbru@yahoo-inc.com)
Received: from mrout1-b.corp.bf1.yahoo.com (mrout1-b.corp.bf1.yahoo.com
	[98.139.253.104])
	by mx1.freebsd.org (Postfix) with ESMTP id 29AA38FC1E;
	Thu, 15 Mar 2012 23:41:26 +0000 (UTC)
Received: from [127.0.0.1] (rideseveral.corp.yahoo.com [10.73.160.231])
	by mrout1-b.corp.bf1.yahoo.com (8.14.4/8.14.4/y.out) with ESMTP id
	q2FNf9Gq039637; Thu, 15 Mar 2012 16:41:09 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yahoo-inc.com;
	s=cobra; t=1331854870;
	bh=1Lz/P9BuoX+V9LYG17HrXgmXX2lKeamxMjirl6TqFpc=;
	h=Subject:From:To:Cc:In-Reply-To:References:Content-Type:Date:
	Message-ID:Mime-Version:Content-Transfer-Encoding;
	b=QWZ03hwLelz23Z0ERUDJ0vx4Rhavj4zPcUsv6a8xqKujIEEPHgVx23IIY48NQy3VD
	sW2e2RQaFDd3xRWBtgjGOBIiRapCoz83zgjlz2gznqGQRub6Wuq/LXZ50Q6c0Fb2HF
	zwX3dO56KEJFBXGpOAMd6tsjXhNk1CQ4olmaoKO8=
From: Sean Bruno <seanbru@yahoo-inc.com>
To: John Baldwin <jhb@freebsd.org>
In-Reply-To: <201203151417.04507.jhb@freebsd.org>
References: <CAAAm0r3Qj+2rf8cx54bcyAXGQezcE8J=xXYPq4W-jDy75r8qew@mail.gmail.com>
	<CAJ-Vmo=2BWQd3an3TT9-YZrLPYDoHs7ZJET360HMQijOWPavOQ@mail.gmail.com>
	<4F5C587B.6010004@gmail.com>  <201203151417.04507.jhb@freebsd.org>
Content-Type: text/plain; charset="UTF-8"
Date: Thu, 15 Mar 2012 16:41:09 -0700
Message-ID: <1331854869.3317.15.camel@powernoodle-l7.corp.yahoo.com>
Mime-Version: 1.0
X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port 
Content-Transfer-Encoding: 7bit
Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>,
	Adrian Chadd <adrian@freebsd.org>,
	Hooman Fazaeli <hoomanfazaeli@gmail.com>,
	Jason Wolfe <nitroboost@gmail.com>
Subject: Re: Intel 82574L interface wedging - em7.3.2/8.2-STABLE
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: Thu, 15 Mar 2012 23:41:27 -0000


> 
> Hmm, so I have yet to test this, but I found several bugs related to transmit 
> in em(4) and igb(4) recently just reading the code.  (Mostly unnecessary
> scheduling of tasks for transmit.)  I've included your change of restarting
> TX when link becomes active.  I've also updated it to fix resume for em
> and igb to DTRT when buf_ring is used, and to not include old-style start
> routines at all when using multiq.  It is at 
> http://www.freebsd.org/~jhb/patches/e1000_txeof2.patch
> 

I think that some of the code being removed originated from our universe
over here at Yahoo.  We were seeing the driver assert IFF_OACTIVE and
never clearing out.

Reviewing this patch at a glance I note that the check of IFF_OACTIVE
was removed, if the kernel can get us out of that state without the
IFF_OACTIVE checks, then I'm good with it.

Sean

ref:

@@ -1497,10 +1509,11 @@
 		if (!drbr_empty(ifp, txr->br))
 			em_mq_start_locked(ifp, txr, NULL);
 #else
-		em_start_locked(ifp, txr);
+		if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
+			em_start_locked(ifp, txr);
 #endif
 		EM_TX_UNLOCK(txr);
-		if (more || (ifp->if_drv_flags & IFF_DRV_OACTIVE)) {
+		if (more) {
 			taskqueue_enqueue(adapter->tq, &adapter->que_task);
 			return;