sctp: reduce memory footprint of sctp_chunk structure

sctp_chunks should be put on a diet.  This is some of the low hanging
fruit that we can strip out.  Changes all the __s8/__u8 flags to
bitfields.  Saves 12 bytes per chunk.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 17 insertions, 14 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ab1c472ea753..0dc1b7267c37 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -731,20 +731,23 @@ struct sctp_chunk {
          */
         struct sk_buff *auth_chunk;
 
-        __u8 rtt_in_progress;   /* Is this chunk used for RTT calculation? */
-        __u8 resent;            /* Has this chunk ever been retransmitted. */
-        __u8 has_tsn;           /* Does this chunk have a TSN yet? */
-        __u8 has_ssn;           /* Does this chunk have a SSN yet? */
-        __u8 singleton;         /* Was this the only chunk in the packet? */
-        __u8 end_of_packet;     /* Was this the last chunk in the packet? */
-        __u8 ecn_ce_done;       /* Have we processed the ECN CE bit? */
-        __u8 pdiscard;          /* Discard the whole packet now? */
-        __u8 tsn_gap_acked;     /* Is this chunk acked by a GAP ACK? */
-        __s8 fast_retransmit;    /* Is this chunk fast retransmitted? */
-        __u8 tsn_missing_report; /* Data chunk missing counter. */
-        __u8 data_accepted;     /* At least 1 chunk in this packet accepted */
-        __u8 auth;              /* IN: was auth'ed | OUT: needs auth */
-        __u8 has_asconf;        /* IN: have seen an asconf before */
+#define SCTP_CAN_FRTX 0x0
+#define SCTP_NEED_FRTX 0x1
+#define SCTP_DONT_FRTX 0x2
+        __u16   rtt_in_progress:1,      /* This chunk used for RTT calc? */
+                resent:1,               /* Has this chunk ever been resent. */
+                has_tsn:1,              /* Does this chunk have a TSN yet? */
+                has_ssn:1,              /* Does this chunk have a SSN yet? */
+                singleton:1,            /* Only chunk in the packet? */
+                end_of_packet:1,        /* Last chunk in the packet? */
+                ecn_ce_done:1,          /* Have we processed the ECN CE bit? */
+                pdiscard:1,             /* Discard the whole packet now? */
+                tsn_gap_acked:1,        /* Is this chunk acked by a GAP ACK? */
+                data_accepted:1,        /* At least 1 chunk accepted */
+                auth:1,                 /* IN: was auth'ed | OUT: needs auth */
+                has_asconf:1,           /* IN: have seen an asconf before */
+                tsn_missing_report:2,   /* Data chunk missing counter. */
+                fast_retransmit:2;      /* Is this chunk fast retransmitted? */
 };
 
 void sctp_chunk_hold(struct sctp_chunk *);