[PATCH net 1/5] sctp: move sent_count to the memory hole in sctp_chunk

[Xin Long]

Now pahole sctp_chunk, it has 2 memory holes:
   struct sctp_chunk {
        struct list_head           list;
        atomic_t                   refcnt;
        /* XXX 4 bytes hole, try to pack */
        ...
        long unsigned int          prsctp_param;
        int                        sent_count;
        /* XXX 4 bytes hole, try to pack */

This patch is to move up sent_count to fill the 1st one and eliminate
the 2nd one.

It's not just another struct compaction, it also fixes the "netperf-
Throughput_Mbps -37.2% regression" issue when overloading the CPU.

Fixes: a6c2f792873a ("sctp: implement prsctp TTL policy")
Signed-off-by: Xin Long <lucien....@gmail.com>
---
 include/net/sctp/structs.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ce93c4b..4f097f5 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -554,6 +554,9 @@ struct sctp_chunk {
 
        atomic_t refcnt;
 
+       /* How many times this chunk have been sent, for prsctp RTX policy */
+       int sent_count;
+
        /* This is our link to the per-transport transmitted list.  */
        struct list_head transmitted_list;
 
@@ -610,9 +613,6 @@ struct sctp_chunk {
         */
        unsigned long prsctp_param;
 
-       /* How many times this chunk have been sent, for prsctp RTX policy */
-       int sent_count;
-
        /* Which association does this belong to?  */
        struct sctp_association *asoc;
 
-- 
2.1.0