zebra: Replace SELECTED_FIB flag with a rib_dest_t pointer

The SELECTED_FIB flag was placed upon the entry that we
have inserted into the kernel.  Remove this flag and replace
with a `rib_dest_t` *selected_fib.  Just keep track of the
selected_fib as we modify it.  This removes allot of
FOREACH_RE loops as that we do not need to find the
entry anymore.

At this point in time I think this is a very minor performance
boost.  Most `rib_dest_t` structures do not typically carry
more than 1 route_entry, but the minute you start having more
than one entry you can and will start having significant processing
time spent finding the selected_fib.

A future commit may re-order the route entries and possibly
keep more pointers on `rib_dest_t` to avoid lookup.  This
is a bit tricky because of the FIB_OVERRIDE code.

Signed-off-by Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 1 insertions, 13 deletions

diff --git a/zebra/zebra_fpm.c b/zebra/zebra_fpm.c
index 7448292d9f..0d0a2cb3bf 100644
--- a/zebra/zebra_fpm.c
+++ b/zebra/zebra_fpm.c
@@ -842,19 +842,7 @@ static inline int zfpm_encode_route(rib_dest_t *dest, struct route_entry *re,
  */
 struct route_entry *zfpm_route_for_update(rib_dest_t *dest)
 {
-	struct route_entry *re;
-
-	RE_DEST_FOREACH_ROUTE (dest, re) {
-		if (!CHECK_FLAG(re->status, ROUTE_ENTRY_SELECTED_FIB))
-			continue;
-
-		return re;
-	}
-
-	/*
-	 * We have no route for this destination.
-	 */
-	return NULL;
+	return dest->selected_fib;
 }
 
 /*