Change the initialization methodology for global variables scheduled

for virtualization.

Instead of initializing the affected global variables at instatiation,
assign initial values to them in initializer functions.  As a rule,
initialization at instatiation for such variables should never be
introduced again from now on.  Furthermore, enclose all instantiations
of such global variables in #ifdef VIMAGE_GLOBALS blocks.

Essentialy, this change should have zero functional impact.  In the next
phase of merging network stack virtualization infrastructure from
p4/vimage branch, the new initialization methology will allow us to
switch between using global variables and their counterparts residing in
virtualization containers with minimum code churn, and in the long run
allow us to intialize multiple instances of such container structures.

Discussed at:	devsummit Strassburg
Reviewed by:	bz, julian
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation

1 files changed, 7 insertions, 4 deletions

diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c
index 3c6ceca..9eb57ba 100644
--- a/sys/netinet/tcp_sack.c
+++ b/sys/netinet/tcp_sack.c
@@ -124,23 +124,26 @@ __FBSDID("$FreeBSD$");
 
 extern struct uma_zone *sack_hole_zone;
 
+#ifdef VIMAGE_GLOBALS
+int tcp_do_sack;
+int tcp_sack_maxholes;
+int tcp_sack_globalmaxholes;
+int tcp_sack_globalholes;
+#endif
+
 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack, CTLFLAG_RW, 0, "TCP SACK");
-int tcp_do_sack = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_sack, OID_AUTO, enable,
     CTLFLAG_RW, tcp_do_sack, 0, "Enable/Disable TCP SACK support");
 TUNABLE_INT("net.inet.tcp.sack.enable", &tcp_do_sack);
 
-static int tcp_sack_maxholes = 128;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_sack, OID_AUTO, maxholes,
     CTLFLAG_RW, tcp_sack_maxholes, 0, 
     "Maximum number of TCP SACK holes allowed per connection");
 
-static int tcp_sack_globalmaxholes = 65536;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_sack, OID_AUTO, globalmaxholes,
     CTLFLAG_RW, tcp_sack_globalmaxholes, 0, 
     "Global maximum number of TCP SACK holes");
 
-static int tcp_sack_globalholes = 0;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_sack, OID_AUTO, globalholes,
     CTLFLAG_RD, tcp_sack_globalholes, 0,
     "Global number of TCP SACK holes currently allocated");