svn commit: r296310 - projects/vnet/sys/netinet

[Bjoern A. Zeeb]

Author: bz
Date: Wed Mar  2 11:18:17 2016
New Revision: 296310
URL: https://svnweb.freebsd.org/changeset/base/296310

Log:
  It looks like as with the safety belt of DELAY(hz) fastened (*) we can
  completely tear down and free all memory for TCP (after r281599).
  
  (*) in theory a few ticks should be good enough to make sure the timers
  are all really gone.  I wonder if we could use a better matric here and
  check a tcbcb count as an optimization.
  
  Sponsored by:	The FreeBSD Foundation

Modified:
  projects/vnet/sys/netinet/tcp_subr.c
  projects/vnet/sys/netinet/tcp_timewait.c

Modified: projects/vnet/sys/netinet/tcp_subr.c
==============================================================================
--- projects/vnet/sys/netinet/tcp_subr.c	Wed Mar  2 10:23:50 2016	(r296309)
+++ projects/vnet/sys/netinet/tcp_subr.c	Wed Mar  2 11:18:17 2016	(r296310)
@@ -660,7 +660,7 @@ tcp_init(void)
 	 * These have to be type stable for the benefit of the timers.
 	 */
 	V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
-	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
+	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 	uma_zone_set_max(V_tcpcb_zone, maxsockets);
 	uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
 
@@ -670,7 +670,7 @@ tcp_init(void)
 
 	TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
 	V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
-	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
+	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 
 	/* Skip initialization of globals for non-default instances. */
 	if (!IS_DEFAULT_VNET(curvnet))
@@ -737,10 +737,18 @@ tcp_destroy(void *unused __unused)
 {
 	int error;
 
+	/*
+	 * All our processes are gone, all our sockets should be cleaned
+	 * up, which means, which should past the tcp_discardcb() calls.
+	 * Sleep to let all tcpcb timers really disappear and then cleanup.
+	 * Timewait will cleanup it's queue and will be ready to go.
+	 */
+	DELAY(hz);
 	tcp_hc_destroy();
 	syncache_destroy();
 	tcp_tw_destroy();
 	in_pcbinfo_destroy(&V_tcbinfo);
+	/* tcp_discardcb() clears the sack_holes up. */
 	uma_zdestroy(V_sack_hole_zone);
 	uma_zdestroy(V_tcpcb_zone);
 

Modified: projects/vnet/sys/netinet/tcp_timewait.c
==============================================================================
--- projects/vnet/sys/netinet/tcp_timewait.c	Wed Mar  2 10:23:50 2016	(r296309)
+++ projects/vnet/sys/netinet/tcp_timewait.c	Wed Mar  2 11:18:17 2016	(r296310)
@@ -186,7 +186,7 @@ tcp_tw_init(void)
 {
 
 	V_tcptw_zone = uma_zcreate("tcptw", sizeof(struct tcptw),
-	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
+	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 	TUNABLE_INT_FETCH("net.inet.tcp.maxtcptw", &maxtcptw);
 	if (maxtcptw == 0)
 		uma_zone_set_max(V_tcptw_zone, tcptw_auto_size());