From owner-svn-src-stable@freebsd.org  Thu Jun  1 08:19:46 2017
Return-Path: <owner-svn-src-stable@freebsd.org>
Delivered-To: svn-src-stable@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6F3A2BF0D45;
 Thu,  1 Jun 2017 08:19:46 +0000 (UTC)
 (envelope-from tuexen@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 3C93E6E38C;
 Thu,  1 Jun 2017 08:19:46 +0000 (UTC)
 (envelope-from tuexen@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v518Jj2D018699;
 Thu, 1 Jun 2017 08:19:45 GMT (envelope-from tuexen@FreeBSD.org)
Received: (from tuexen@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id v518JjLE018698;
 Thu, 1 Jun 2017 08:19:45 GMT (envelope-from tuexen@FreeBSD.org)
Message-Id: <201706010819.v518JjLE018698@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: tuexen set sender to
 tuexen@FreeBSD.org using -f
From: Michael Tuexen <tuexen@FreeBSD.org>
Date: Thu, 1 Jun 2017 08:19:45 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org
Subject: svn commit: r319397 - stable/11/sys/netinet
X-SVN-Group: stable-11
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-stable@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: SVN commit messages for all the -stable branches of the src tree
 <svn-src-stable.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-stable>, 
 <mailto:svn-src-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-stable/>
List-Post: <mailto:svn-src-stable@freebsd.org>
List-Help: <mailto:svn-src-stable-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-stable>,
 <mailto:svn-src-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 01 Jun 2017 08:19:46 -0000

Author: tuexen
Date: Thu Jun  1 08:19:45 2017
New Revision: 319397
URL: https://svnweb.freebsd.org/changeset/base/319397

Log:
  MFC r314155:
  
  TCP window updates are only sent if the window can be increased by at
  least 2 * MSS. However, if the receive buffer size is small, this might
  be impossible. Add back a criterion to send a TCP window update if
  the window can be increased by at least half of the receive buffer size.
  This condition was removed in r242252. This patch simply brings it back.
  
  PR:			211003
  Reviewed by:		gnn
  Differential Revision:	https://reviews.freebsd.org/D9475

Modified:
  stable/11/sys/netinet/tcp_output.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/netinet/tcp_output.c
==============================================================================
--- stable/11/sys/netinet/tcp_output.c	Thu Jun  1 08:15:33 2017	(r319396)
+++ stable/11/sys/netinet/tcp_output.c	Thu Jun  1 08:19:45 2017	(r319397)
@@ -688,6 +688,8 @@ after_sack_rexmit:
 		     recwin <= (long)(so->so_rcv.sb_hiwat / 8) ||
 		     so->so_rcv.sb_hiwat <= 8 * tp->t_maxseg))
 			goto send;
+		if (2 * adv >= (int32_t)so->so_rcv.sb_hiwat)
+			goto send;
 	}
 dontupdate: