net: sctp: Don't use 64 kilobyte lookup table for four elements

Seemingly innocuous sctp_trans_state_to_prio_map[] array
is way bigger than it looks, since
"[SCTP_UNKNOWN] = 2" expands into "[0xffff] = 2" !

This patch replaces it with switch() statement.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
CC: linux-sctp@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 197c3f59ecbf1d7975a987e57c13023ac9e2b357..b00f1f9611d64a7f46fdd37460d9c5ec9711f37f 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1208,20 +1208,22 @@ void sctp_assoc_update(struct sctp_association *asoc,
  *   within this document.
  *
  * Our basic strategy is to round-robin transports in priorities
- * according to sctp_state_prio_map[] e.g., if no such
+ * according to sctp_trans_score() e.g., if no such
  * transport with state SCTP_ACTIVE exists, round-robin through
  * SCTP_UNKNOWN, etc. You get the picture.
  */
-static const u8 sctp_trans_state_to_prio_map[] = {
-       [SCTP_ACTIVE]   = 3,    /* best case */
-       [SCTP_UNKNOWN]  = 2,
-       [SCTP_PF]       = 1,
-       [SCTP_INACTIVE] = 0,    /* worst case */
-};
-
 static u8 sctp_trans_score(const struct sctp_transport *trans)
 {
-       return sctp_trans_state_to_prio_map[trans->state];
+       switch (trans->state) {
+       case SCTP_ACTIVE:
+               return 3;       /* best case */
+       case SCTP_UNKNOWN:
+               return 2;
+       case SCTP_PF:
+               return 1;
+       default: /* case SCTP_INACTIVE */
+               return 0;       /* worst case */
+       }
 }
 
 static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,