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Message-ID: <20080725121130.GB12725@hmsreliant.think-freely.org>
Date: Fri, 25 Jul 2008 08:11:30 -0400
From: Neil Horman <nhorman@...driver.com>
To: linux-sctp@...r.kernel.org, netdev@...r.kernel.org,
vladislav.yasevich@...com
Cc: nhorman@...driver.com
Subject: [PATCH] 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@...driver.com>
include/net/sctp/structs.h | 31 +++++++++++++++++--------------
net/sctp/output.c | 3 ++-
net/sctp/outqueue.c | 14 +++++++-------
net/sctp/sm_make_chunk.c | 2 +-
4 files changed, 27 insertions(+), 23 deletions(-)
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 7f25195..cadd7a6 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_NO_FRT 0x0
+#define SCTP_NEED_FRT 0x1
+#define SCTP_CANT_FRT 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? */
+ tsn_missing_report:1, /* Data chunk missing counter. */
+ 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 */
+ 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 7e7e612..6ee3475 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -709,7 +709,8 @@ 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_CANT_FRT) ||
+ (chunk->fast_retransmit == SCTP_NO_FRT))
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 ace6770..b1ebcc6 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -418,7 +418,7 @@ 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_FRT)) ||
(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
@@ -648,8 +648,8 @@ 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_FRT)
+ chunk->fast_retransmit = SCTP_CANT_FRT;
/* Force start T3-rtx timer when fast retransmitting
* the earliest outstanding TSN
@@ -678,8 +678,8 @@ 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_FRT)
+ chunk1->fast_retransmit = SCTP_CANT_FRT;
}
}
@@ -1635,7 +1635,7 @@ 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_NEED_FRT) &&
!chunk->tsn_gap_acked &&
TSN_lt(tsn, highest_new_tsn_in_sack)) {
@@ -1660,7 +1660,7 @@ static void sctp_mark_missing(struct sctp_outq *q,
*/
if (chunk->tsn_missing_report >= 3) {
- chunk->fast_retransmit = 1;
+ chunk->fast_retransmit = SCTP_NEED_FRT;
do_fast_retransmit = 1;
}
}
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 3b55ad1..71f4178 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1195,7 +1195,7 @@ 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_NO_FRT;
/* If this is a fragmented message, track all fragments
* of the message (for SEND_FAILED).
--
/****************************************************
* Neil Horman <nhorman@...driver.com>
* Software Engineer, Red Hat
****************************************************/
--
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