sctp: reuse sent_count to avoid retransmitted chunks for RTT measurements

Now sctp uses chunk->resent to record if a chunk is retransmitted, for
RTT measurements with retransmitted DATA chunks. chunk->sent_count was
introduced to record how many times one chunk has been sent for prsctp
RTX policy before. We actually can know if one chunk is retransmitted
by checking chunk->sent_count is greater than 1.

This patch is to remove resent from sctp_chunk and reuse sent_count
to avoid retransmitted chunks for RTT measurements.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2016-10-08 11:36:05 +08:00 committed by David S. Miller
parent 0f505b1ae6
commit cc6ac9bccf
3 changed files with 4 additions and 5 deletions

View File

@ -641,7 +641,6 @@ struct sctp_chunk {
#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? */
@ -656,6 +655,7 @@ struct sctp_chunk {
fast_retransmit:2; /* Is this chunk fast retransmitted? */
};
#define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
void sctp_chunk_hold(struct sctp_chunk *);
void sctp_chunk_put(struct sctp_chunk *);
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,

View File

@ -552,7 +552,8 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
* for a given destination transport address.
*/
if (!chunk->resent && !tp->rto_pending) {
if (!sctp_chunk_retransmitted(chunk) &&
!tp->rto_pending) {
chunk->rtt_in_progress = 1;
tp->rto_pending = 1;
}

View File

@ -507,8 +507,6 @@ void sctp_retransmit_mark(struct sctp_outq *q,
transport->rto_pending = 0;
}
chunk->resent = 1;
/* Move the chunk to the retransmit queue. The chunks
* on the retransmit queue are always kept in order.
*/
@ -1439,7 +1437,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
* instance).
*/
if (!tchunk->tsn_gap_acked &&
!tchunk->resent &&
!sctp_chunk_retransmitted(tchunk) &&
tchunk->rtt_in_progress) {
tchunk->rtt_in_progress = 0;
rtt = jiffies - tchunk->sent_at;