Thread (1 message) 1 message, 1 author, 2015-09-28

Re: [PATCH] net: sctp: Don't use 64 kilobyte lookup table for four elements

flat view

From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Date: 2015-09-28 12:30:38
Also in: linux-sctp, lkml

On Sat, Sep 26, 2015 at 08:53:14PM +0200, Denys Vlasenko wrote:
quoted hunk
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 <redacted>
CC: Vlad Yasevich <redacted>
CC: Neil Horman <nhorman@tuxdriver.com>
CC: linux-sctp@vger.kernel.org
CC: linux-kernel@vger.kernel.org
---
 net/sctp/associola.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 197c3f5..dae51ac 100644
--- 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 */
+	}
 }
Nice finding, but please make above comments aligned to the column.
Then it looks good to me.

When posting v2, also post to netdev@vger.kernel.org, it's where Dave
collects sctp (amongst others) patches. Kernel patches are not collected
on linux-sctp@, though they are posted there too but for reviewing only.

Thanks,
Marcelo
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help