sctp: Optimize SFR-CACC transport list walking during SACK processing

There is a possibility of walking the transport list twice during
SACK processing when doing SFR-CACC algorithm.  We can restructure
the code to only do this once.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
This commit is contained in:
Vlad Yasevich 2008-06-19 18:17:24 -04:00
parent 2cd9b822bf
commit ab5216a5bd

View File

@ -1145,27 +1145,31 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
* on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
* cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
* all destinations.
*/
if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
primary->cacc.changeover_active = 0;
list_for_each_entry(transport, transport_list,
transports) {
transport->cacc.cycling_changeover = 0;
}
}
/*
* SFR-CACC algorithm:
* 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
* is set the receiver of the SACK MUST take the following actions:
*
* A) Initialize the cacc_saw_newack to 0 for all destination
* addresses.
*
* Only bother if changeover_active is set. Otherwise, this is
* totally suboptimal to do on every SACK.
*/
if (gap_ack_blocks &&
primary->cacc.changeover_active) {
list_for_each_entry(transport, transport_list, transports) {
transport->cacc.cacc_saw_newack = 0;
if (primary->cacc.changeover_active) {
u8 clear_cycling = 0;
if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
primary->cacc.changeover_active = 0;
clear_cycling = 1;
}
if (clear_cycling || gap_ack_blocks) {
list_for_each_entry(transport, transport_list,
transports) {
if (clear_cycling)
transport->cacc.cycling_changeover = 0;
if (gap_ack_blocks)
transport->cacc.cacc_saw_newack = 0;
}
}
}