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, 4 insertions, 1 deletions

diff --git a/sys/net/if_loop.c b/sys/net/if_loop.c
index 09bbb55..ba49d76 100644
--- a/sys/net/if_loop.c
+++ b/sys/net/if_loop.c
@@ -96,7 +96,9 @@ int		looutput(struct ifnet *ifp, struct mbuf *m,
 static int	lo_clone_create(struct if_clone *, int, caddr_t);
 static void	lo_clone_destroy(struct ifnet *);
 
-struct ifnet *loif = NULL;			/* Used externally */
+#ifdef VIMAGE_GLOBALS
+struct ifnet *loif;			/* Used externally */
+#endif
 
 IFC_SIMPLE_DECLARE(lo, 1);
 
@@ -142,6 +144,7 @@ loop_modevent(module_t mod, int type, void *data)
 
 	switch (type) {
 	case MOD_LOAD:
+		V_loif = NULL;
 		if_clone_attach(&lo_cloner);
 		break;