diff options
author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2006-11-27 09:22:48 -0500 |
---|---|---|
committer | David S. Miller <davem@sunset.davemloft.net> | 2006-12-03 00:30:36 -0500 |
commit | f5c2d6367b04fd5ba98a5f9846b5fb870423968a (patch) | |
tree | 139687b3ec6b86b1938e7d55571880b9a88bf936 /net | |
parent | 90feeb951f61a80d3a8f8e5ced25b9ec78867eaf (diff) |
[DCCP] ccid3: Simplify control flow in the calculation of t_ipi
This patch performs a simplifying (performance) optimisation:
In each call of the inline function ccid3_calc_new_t_ipi(), the state is
tested against TFRC_SSTATE_NO_FBACK. This is expensive when the function
is called very often. A simpler solution, implemented by this patch, is
to adapt the control flow.
Background:
Diffstat (limited to 'net')
-rw-r--r-- | net/dccp/ccids/ccid3.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index d7b688e9f983..df88c54b2ec5 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c | |||
@@ -103,13 +103,7 @@ static void ccid3_hc_tx_set_state(struct sock *sk, | |||
103 | /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */ | 103 | /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */ |
104 | static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx) | 104 | static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx) |
105 | { | 105 | { |
106 | /* | 106 | hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_x); |
107 | * If no feedback spec says t_ipi is 1 second (set elsewhere and then | ||
108 | * doubles after every no feedback timer (separate function) | ||
109 | */ | ||
110 | if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) | ||
111 | hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, | ||
112 | hctx->ccid3hctx_x); | ||
113 | } | 107 | } |
114 | 108 | ||
115 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ | 109 | /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ |
@@ -395,6 +389,8 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len) | |||
395 | "as a data packet", dccp_role(sk)); | 389 | "as a data packet", dccp_role(sk)); |
396 | return; | 390 | return; |
397 | case TFRC_SSTATE_NO_FBACK: | 391 | case TFRC_SSTATE_NO_FBACK: |
392 | /* t_nom, t_ipi, delta do not change until feedback arrives */ | ||
393 | return; | ||
398 | case TFRC_SSTATE_FBACK: | 394 | case TFRC_SSTATE_FBACK: |
399 | if (len > 0) { | 395 | if (len > 0) { |
400 | timeval_sub_usecs(&hctx->ccid3hctx_t_nom, | 396 | timeval_sub_usecs(&hctx->ccid3hctx_t_nom, |