net: sctp: reorder sctp_globals to reduce cacheline usage

Reduce cacheline usage from 2 to 1 cacheline for sctp_globals structure. By
reordering elements, we can close gaps and simply achieve the following:

Current situation:
  /* size: 80, cachelines: 2, members: 10 */
  /* sum members: 57, holes: 4, sum holes: 16 */
  /* padding: 7 */
  /* last cacheline: 16 bytes */

Afterwards:
  /* size: 64, cachelines: 1, members: 10 */
  /* padding: 7 */

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 422db6cc3214b77264eccec4288ece4315f045e7..2174d8da0770a5285d3d937a1174eb9e52dd2a27 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -113,29 +113,27 @@ struct sctp_hashbucket {
 
 /* The SCTP globals structure. */
 extern struct sctp_globals {
-       /* The following variables are implementation specific.  */
-
-       /* Default initialization values to be applied to new associations. */
-       __u16 max_instreams;
-       __u16 max_outstreams;
-
        /* This is a list of groups of functions for each address
         * family that we support.
         */
        struct list_head address_families;
 
        /* This is the hash of all endpoints. */
-       int ep_hashsize;
        struct sctp_hashbucket *ep_hashtable;
-
        /* This is the hash of all associations. */
-       int assoc_hashsize;
        struct sctp_hashbucket *assoc_hashtable;
-
        /* This is the sctp port control hash.  */
-       int port_hashsize;
        struct sctp_bind_hashbucket *port_hashtable;
 
+       /* Sizes of above hashtables. */
+       int ep_hashsize;
+       int assoc_hashsize;
+       int port_hashsize;
+
+       /* Default initialization values to be applied to new associations. */
+       __u16 max_instreams;
+       __u16 max_outstreams;
+
        /* Flag to indicate whether computing and verifying checksum
         * is disabled. */
         bool checksum_disable;