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>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ab1c472ea75375a45dead4368cabd96b30941b2e..0dc1b7267c37fae9ec14ebaf0d2c3fa47b17f416 100644 (file)
--- 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 *);

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 225c7123c41f8b2dfa3a629b7bb8590133ab146e..c3f417f7ec6e8d305ae3e50ef7aa15fd33170080 100644 (file)
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -699,7 +699,7 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
         *    When a Fast Retransmit is being performed the sender SHOULD
         *    ignore the value of cwnd and SHOULD NOT delay retransmission.
         */
-       if (chunk->fast_retransmit <= 0)
+       if (chunk->fast_retransmit != SCTP_NEED_FRTX)
                if (transport->flight_size >= transport->cwnd) {
                        retval = SCTP_XMIT_RWND_FULL;
                        goto finish;

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index da8d846301c18d8f07ea8a9c4b78db91afbf6bb0..247ebc95c1e59186ade6e76aec48fd3c57f7738c 100644 (file)
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -420,7 +420,7 @@ void sctp_retransmit_mark(struct sctp_outq *q,
                 * be added to the retransmit queue.
                 */
                if ((reason == SCTP_RTXR_FAST_RTX  &&
-                           (chunk->fast_retransmit > 0)) ||
+                           (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
                    (reason != SCTP_RTXR_FAST_RTX  && !chunk->tsn_gap_acked)) {
                        /* If this chunk was sent less then 1 rto ago, do not
                         * retransmit this chunk, but give the peer time
@@ -650,8 +650,8 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
                        /* Mark the chunk as ineligible for fast retransmit
                         * after it is retransmitted.
                         */
-                       if (chunk->fast_retransmit > 0)
-                               chunk->fast_retransmit = -1;
+                       if (chunk->fast_retransmit == SCTP_NEED_FRTX)
+                               chunk->fast_retransmit = SCTP_DONT_FRTX;
 
                        /* Force start T3-rtx timer when fast retransmitting
                         * the earliest outstanding TSN
@@ -680,8 +680,8 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
         */
        if (rtx_timeout || fast_rtx) {
                list_for_each_entry(chunk1, lqueue, transmitted_list) {
-                       if (chunk1->fast_retransmit > 0)
-                               chunk1->fast_retransmit = -1;
+                       if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
+                               chunk1->fast_retransmit = SCTP_DONT_FRTX;
                }
        }
 
@@ -1656,7 +1656,7 @@ static void sctp_mark_missing(struct sctp_outq *q,
                 * chunk if it has NOT been fast retransmitted or marked for
                 * fast retransmit already.
                 */
-               if (!chunk->fast_retransmit &&
+               if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
                    !chunk->tsn_gap_acked &&
                    TSN_lt(tsn, highest_new_tsn_in_sack)) {
 
@@ -1681,7 +1681,7 @@ static void sctp_mark_missing(struct sctp_outq *q,
                 */
 
                if (chunk->tsn_missing_report >= 3) {
-                       chunk->fast_retransmit = 1;
+                       chunk->fast_retransmit = SCTP_NEED_FRTX;
                        do_fast_retransmit = 1;
                }
        }

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index d68869f966c3b3b99fb70f8361cae85452f98632..99fe0747cc968482a7f35900045e31e25dcef5a7 100644 (file)
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1211,7 +1211,7 @@ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
         */
        retval->tsn_missing_report = 0;
        retval->tsn_gap_acked = 0;
-       retval->fast_retransmit = 0;
+       retval->fast_retransmit = SCTP_CAN_FRTX;
 
        /* If this is a fragmented message, track all fragments
         * of the message (for SEND_FAILED).