From owner-svn-src-all@FreeBSD.ORG  Fri Mar 15 13:01:02 2013
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by hub.freebsd.org (Postfix) with ESMTP id 90E547A7
 for <svn-src-all@freebsd.org>; Fri, 15 Mar 2013 13:01:02 +0000 (UTC)
 (envelope-from andre@freebsd.org)
Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2])
 by mx1.freebsd.org (Postfix) with ESMTP id 08B0ED4D
 for <svn-src-all@freebsd.org>; Fri, 15 Mar 2013 13:01:01 +0000 (UTC)
Received: (qmail 64292 invoked from network); 15 Mar 2013 14:13:02 -0000
Received: from c00l3r.networx.ch (HELO [127.0.0.1]) ([62.48.2.2])
 (envelope-sender <andre@freebsd.org>)
 by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP
 for <glebius@FreeBSD.org>; 15 Mar 2013 14:13:02 -0000
Message-ID: <51431B89.5010501@freebsd.org>
Date: Fri, 15 Mar 2013 14:00:57 +0100
From: Andre Oppermann <andre@freebsd.org>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64;
 rv:17.0) Gecko/20130215 Thunderbird/17.0.3
MIME-Version: 1.0
To: Gleb Smirnoff <glebius@FreeBSD.org>
Subject: Re: svn commit: r248323 - head/sys/netinet
References: <201303151253.r2FCrsSs016150@svn.freebsd.org>
In-Reply-To: <201303151253.r2FCrsSs016150@svn.freebsd.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
 src-committers@freebsd.org
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 15 Mar 2013 13:01:02 -0000

On 15.03.2013 13:53, Gleb Smirnoff wrote:
> Author: glebius
> Date: Fri Mar 15 12:53:53 2013
> New Revision: 248323
> URL: http://svnweb.freebsd.org/changeset/base/248323
>
> Log:
>    - Use m_getcl() instead of hand allocating.
>
>    Sponsored by:	Nginx, Inc.
>
> Modified:
>    head/sys/netinet/tcp_output.c
>
> Modified: head/sys/netinet/tcp_output.c
> ==============================================================================
> --- head/sys/netinet/tcp_output.c	Fri Mar 15 12:52:59 2013	(r248322)
> +++ head/sys/netinet/tcp_output.c	Fri Mar 15 12:53:53 2013	(r248323)
> @@ -842,23 +842,19 @@ send:
>   			TCPSTAT_INC(tcps_sndpack);
>   			TCPSTAT_ADD(tcps_sndbyte, len);
>   		}
> -		MGETHDR(m, M_NOWAIT, MT_DATA);
> +#ifdef INET6
> +		if (MHLEN < hdrlen + max_linkhdr)
> +			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
> +		else
> +#endif
> +			m = m_gethdr(M_NOWAIT, MT_DATA);
> +

m = m_getm2(hdrlen + max_linkhdr, M_NOWAIT, MT_DATA, M_PKTHDR);

would be even more compact.  Since max_linkhdr could be large as well,
the possibility of a cluster applies to IPv4 too.

-- 
Andre

>   		if (m == NULL) {
>   			SOCKBUF_UNLOCK(&so->so_snd);
>   			error = ENOBUFS;
>   			goto out;
>   		}
> -#ifdef INET6
> -		if (MHLEN < hdrlen + max_linkhdr) {
> -			MCLGET(m, M_NOWAIT);
> -			if ((m->m_flags & M_EXT) == 0) {
> -				SOCKBUF_UNLOCK(&so->so_snd);
> -				m_freem(m);
> -				error = ENOBUFS;
> -				goto out;
> -			}
> -		}
> -#endif
> +
>   		m->m_data += max_linkhdr;
>   		m->m_len = hdrlen;
>
>
>