From owner-svn-soc-all@freebsd.org  Mon Jun 27 12:48:56 2016
Return-Path: <owner-svn-soc-all@freebsd.org>
Delivered-To: svn-soc-all@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 84CFCB72B6A
 for <svn-soc-all@mailman.ysv.freebsd.org>;
 Mon, 27 Jun 2016 12:48:56 +0000 (UTC)
 (envelope-from vincenzo@FreeBSD.org)
Received: from socsvn.freebsd.org (socsvn.freebsd.org
 [IPv6:2001:1900:2254:206a::50:2])
 (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 7876B2234
 for <svn-soc-all@FreeBSD.org>; Mon, 27 Jun 2016 12:48:56 +0000 (UTC)
 (envelope-from vincenzo@FreeBSD.org)
Received: from socsvn.freebsd.org ([127.0.1.124])
 by socsvn.freebsd.org (8.15.2/8.15.2) with ESMTP id u5RCmutF081318
 for <svn-soc-all@FreeBSD.org>; Mon, 27 Jun 2016 12:48:56 GMT
 (envelope-from vincenzo@FreeBSD.org)
Received: (from www@localhost)
 by socsvn.freebsd.org (8.15.2/8.15.2/Submit) id u5RCmtCT081316
 for svn-soc-all@FreeBSD.org; Mon, 27 Jun 2016 12:48:55 GMT
 (envelope-from vincenzo@FreeBSD.org)
Date: Mon, 27 Jun 2016 12:48:55 GMT
Message-Id: <201606271248.u5RCmtCT081316@socsvn.freebsd.org>
X-Authentication-Warning: socsvn.freebsd.org: www set sender to
 vincenzo@FreeBSD.org using -f
From: vincenzo@FreeBSD.org
To: svn-soc-all@FreeBSD.org
Subject: socsvn commit: r305588 - soc2016/vincenzo/head/sys/dev/netmap
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-soc-all@freebsd.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: SVN commit messages for the entire Summer of Code repository
 <svn-soc-all.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-soc-all>,
 <mailto:svn-soc-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-soc-all/>
List-Post: <mailto:svn-soc-all@freebsd.org>
List-Help: <mailto:svn-soc-all-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-soc-all>,
 <mailto:svn-soc-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 27 Jun 2016 12:48:56 -0000

Author: vincenzo
Date: Mon Jun 27 12:48:55 2016
New Revision: 305588
URL: http://svnweb.FreeBSD.org/socsvn/?view=rev&rev=305588

Log:
   freebsd: ptnet_transmit: ptnet_sync_tail when running out of slots

Modified:
  soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c

Modified: soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c
==============================================================================
--- soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c	Mon Jun 27 12:48:45 2016	(r305587)
+++ soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c	Mon Jun 27 12:48:55 2016	(r305588)
@@ -1219,16 +1219,26 @@
 	ring = kring->ring;
 	lim = kring->nkr_num_slots - 1;
 
-	/* Update hwcur and hwtail (completed TX slots) as known by the host,
-	 * by reading from CSB. */
-	ptnet_sync_tail(ptring, kring);
-
+	/* Initialize transmission state variables. */
 	head = ring->head;
 	slot = ring->slot + head;
 	nmbuf = NMB(na, slot);
 	nmbuf_bytes = 0;
 
-	while (head != ring->tail) {
+	for (;;) {
+		if (head == ring->tail) {
+			/* We ran out of slot, let's see if the host has
+			 * freed up some, by reading hwcur and hwtail from
+			 * the CSB. */
+			ptnet_sync_tail(ptring, kring);
+		}
+
+		if (head == ring->tail) {
+			/* Still no slots available, let's stop and wait
+			 * for interrupts. */
+			break;
+		}
+
 		m = drbr_peek(ifp, pq->bufring);
 		if (!m) {
 			break;