From owner-freebsd-net@FreeBSD.ORG  Thu Dec 19 20:03:35 2013
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
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 2EA611F1;
 Thu, 19 Dec 2013 20:03:35 +0000 (UTC)
Received: from mail-pb0-x229.google.com (mail-pb0-x229.google.com
 [IPv6:2607:f8b0:400e:c01::229])
 (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id E0CE613D0;
 Thu, 19 Dec 2013 20:03:34 +0000 (UTC)
Received: by mail-pb0-f41.google.com with SMTP id jt11so1621464pbb.0
 for <multiple recipients>; Thu, 19 Dec 2013 12:03:34 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject
 :references:in-reply-to:content-type:content-transfer-encoding;
 bh=51dWnUG7SFfG/wT0hLsbTLAA3fqf9gqN6R9veaqdoE8=;
 b=a7wIXYMWK3HVGsAF+Iq092s1nQmquPhvNyOFRKgMA9H2popLxo6rWD9rRwi6v3jnC4
 GlRX3MmJXyZHeaE3L7rYDY+V9jw7Xi6XvpkvBd53+iIgjQ0rAexAK2qmCs2FSOLylxbz
 9ZSC61tikW6JG71ykzQ4MYTxydc3ErJlyk0i4y4/bx/tcvr/JpOx3tmlKnOJVmEq9PNg
 TvMiwbc44bBNe+uup/E441l/vmSAfdG0VIiQ3llaqFUP4R9jxrFgLeHcAo1hn4HisJ5z
 lxJXTDQpDNIfKsBBwcYtvRPQIAVrx2WTB9dNzbu4ze8C1XYlwpHBwg44x8t+IAdDxMv7
 /NQA==
X-Received: by 10.69.21.1 with SMTP id hg1mr3751254pbd.67.1387483414124;
 Thu, 19 Dec 2013 12:03:34 -0800 (PST)
Received: from [10.192.166.0] (stargate.chelsio.com. [67.207.112.58])
 by mx.google.com with ESMTPSA id ye1sm11908815pab.19.2013.12.19.12.03.31
 for <multiple recipients>
 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
 Thu, 19 Dec 2013 12:03:32 -0800 (PST)
Sender: Navdeep Parhar <nparhar@gmail.com>
Message-ID: <52B35113.9050108@FreeBSD.org>
Date: Thu, 19 Dec 2013 12:03:31 -0800
From: Navdeep Parhar <np@FreeBSD.org>
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64;
 rv:24.0) Gecko/20100101 Thunderbird/24.2.0
MIME-Version: 1.0
To: Adrian Chadd <adrian@freebsd.org>, 
 Gleb Smirnoff <glebius@freebsd.org>
Subject: Re: Removing queue length check in ip_output (was Re: buf_ring in
 HEAD is racy)
References: <CAJ-VmomyPq_2K-MFhb7vt6MM7RBbmn7yaTzUXb7+N7TbW1RmHQ@mail.gmail.com>
 <20131219151606.GB71033@FreeBSD.org>
 <CAJ-Vmo=jCo-H8BwybFS3uaS3xQ4pxSz-hpxyEg0z2g3KSoErwQ@mail.gmail.com>
 <CAJ-VmonYRb9jQKbXLuurQrrjaUzQcwiRze0O7g2A5s=KPBjDKw@mail.gmail.com>
In-Reply-To: <CAJ-VmonYRb9jQKbXLuurQrrjaUzQcwiRze0O7g2A5s=KPBjDKw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: Jack F Vogel <jfv@freebsd.org>,
 Michael Tuexen <Michael.Tuexen@lurchi.franken.de>,
 Ryan Stone <rysto32@gmail.com>, freebsd-net <freebsd-net@freebsd.org>
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/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, 19 Dec 2013 20:03:35 -0000

On 12/19/13 11:59, Adrian Chadd wrote:
> How's this?
> 
> Index: sys/netinet/ip_output.c
> ===================================================================
> --- sys/netinet/ip_output.c     (revision 259474)
> +++ sys/netinet/ip_output.c     (working copy)
> @@ -123,7 +123,9 @@
>         struct mbuf *m0;
>         int hlen = sizeof (struct ip);
>         int mtu;
> +#if 0
>         int n;  /* scratchpad */
> +#endif
>         int error = 0;
>         struct sockaddr_in *dst;
>         const struct sockaddr_in *gw;
> @@ -431,6 +433,25 @@
>         }
> 
>         /*
> +        * Both in the SMP world, pre-emption world if_transmit() world,
> +        * the following code doesn't really function as intended any further.

Doesn't make sense in the tx multiqueue world either.  (which queue is
this piece of code checking?)

Navdeep