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, 11 insertions, 8 deletions

diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index b3a010b..ab92905 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -87,39 +87,42 @@ __FBSDID("$FreeBSD$");
 extern struct mbuf *m_copypack();
 #endif
 
-int path_mtu_discovery = 1;
+#ifdef VIMAGE_GLOBALS
+int path_mtu_discovery;
+int ss_fltsz;
+int ss_fltsz_local;
+int tcp_do_newreno;
+int tcp_do_tso;
+int tcp_do_autosndbuf;
+int tcp_autosndbuf_inc;
+int tcp_autosndbuf_max;
+#endif
+
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, path_mtu_discovery,
 	CTLFLAG_RW, path_mtu_discovery, 1, "Enable Path MTU Discovery");
 
-int ss_fltsz = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO,
 	slowstart_flightsize, CTLFLAG_RW,
 	ss_fltsz, 1, "Slow start flight size");
 
-int ss_fltsz_local = 4;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO,
 	local_slowstart_flightsize, CTLFLAG_RW,
 	ss_fltsz_local, 1, "Slow start flight size for local networks");
 
-int     tcp_do_newreno = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, newreno, CTLFLAG_RW,
 	tcp_do_newreno, 0, "Enable NewReno Algorithms");
 
-int	tcp_do_tso = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, tso, CTLFLAG_RW,
 	tcp_do_tso, 0, "Enable TCP Segmentation Offload");
 
-int	tcp_do_autosndbuf = 1;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, sendbuf_auto,
 	CTLFLAG_RW,
 	tcp_do_autosndbuf, 0, "Enable automatic send buffer sizing");
 
-int	tcp_autosndbuf_inc = 8*1024;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, sendbuf_inc,
 	CTLFLAG_RW, tcp_autosndbuf_inc, 0,
 	"Incrementor step size of automatic send buffer");
 
-int	tcp_autosndbuf_max = 256*1024;
 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, sendbuf_max,
 	CTLFLAG_RW, tcp_autosndbuf_max, 0,
 	"Max size of automatic send buffer");