* [PATCH 8/10]: Larger initial windows
@ 2006-11-24 16:20 Gerrit Renker
2006-11-26 21:15 ` Ian McDonald
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Gerrit Renker @ 2006-11-24 16:20 UTC (permalink / raw)
To: dccp
[CCID 3]: Larger initial windows
This implements the larger-initial-windows feature for CCID 3, as described
in section 5 of RFC 4342. When the first feedback packet arrives, the sender
can send up to 2..4 packets per RTT, instead of just one.
The patch further
* reduces the number of timestamping calls by passing the timestamp value
(which is computed in one of the calling functions anyway) as argument
* renames one constant with a very long name into one which is shorter and
resembles the one in RFC 3448 (t_mbi)
* simplifies some of the min_t/max_t cases where both `x', `y' have the same
type
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
---
net/dccp/ccids/ccid3.c | 75 +++++++++++++++++++++++++++----------------------
net/dccp/ccids/ccid3.h | 4 +-
2 files changed, 44 insertions(+), 35 deletions(-)
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -129,35 +129,42 @@ static inline void ccid3_update_send_tim
* If X has changed, we also update the scheduled send time t_now,
* the inter-packet interval t_ipi, and the delta value.
*/
-static void ccid3_hc_tx_update_x(struct sock *sk)
+static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
+
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
const __u32 old_x = hctx->ccid3hctx_x;
DCCP_BUG_ON(hctx->ccid3hctx_rtt = 0);
- /* To avoid large error in calcX */
- if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
- hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
- hctx->ccid3hctx_rtt,
- hctx->ccid3hctx_p);
- hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
- 2 * hctx->ccid3hctx_x_recv),
- (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME));
- } else {
- struct timeval now;
+ /* Compute X after the first feedback packet has arrived */
+ if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
+ /* This implements `Larger Initial Windows' [RFC 4342, sec. 5]
+ * We deviate in that we use `s' instead of `MSS'. */
+ u16 w_init = max( 4 * hctx->ccid3hctx_s,
+ max( 2 * hctx->ccid3hctx_s, 4380));
+ hctx->ccid3hctx_x = usecs_div(w_init, hctx->ccid3hctx_rtt);
+ hctx->ccid3hctx_t_ld = *now;
+
+ /* To avoid large error in calcX */
+ } else if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
+ hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_rtt,
+ hctx->ccid3hctx_p);
+ hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
+ hctx->ccid3hctx_x_recv * 2),
+ hctx->ccid3hctx_s / TFRC_t_mbi );
+
+ } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >+ hctx->ccid3hctx_rtt) {
+ hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
+ hctx->ccid3hctx_x ) * 2,
+ usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_rtt) );
+ hctx->ccid3hctx_t_ld = *now;
+ } else
+ ccid3_pr_debug("Not changing X\n");
- dccp_timestamp(sk, &now);
- if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >- hctx->ccid3hctx_rtt) {
- hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
- hctx->ccid3hctx_x) * 2,
- usecs_div(hctx->ccid3hctx_s,
- hctx->ccid3hctx_rtt));
- hctx->ccid3hctx_t_ld = now;
- }
- }
if(hctx->ccid3hctx_x != old_x)
ccid3_update_send_time(hctx);
}
@@ -185,6 +192,7 @@ static void ccid3_hc_tx_no_feedback_time
struct sock *sk = (struct sock *)data;
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
unsigned long next_tmout = USEC_PER_SEC / 5;
+ struct timeval now;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
@@ -200,10 +208,8 @@ static void ccid3_hc_tx_no_feedback_time
case TFRC_SSTATE_NO_FBACK:
/* Halve send rate */
hctx->ccid3hctx_x /= 2;
- if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME))
- hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
- TFRC_MAX_BACK_OFF_TIME);
+ if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s / TFRC_t_mbi))
+ hctx->ccid3hctx_x = hctx->ccid3hctx_s / TFRC_t_mbi;
ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
"bytes/s\n",
@@ -240,12 +246,13 @@ static void ccid3_hc_tx_no_feedback_time
if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
- hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
+ hctx->ccid3hctx_s / (2 * TFRC_t_mbi));
else
hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
/* Update sending rate */
- ccid3_hc_tx_update_x(sk);
+ dccp_timestamp(sk, &now);
+ ccid3_hc_tx_update_x(sk, &now);
}
/*
* Schedule no feedback timer to expire in
@@ -488,10 +495,9 @@ static void ccid3_hc_tx_packet_recv(stru
*
* q is a constant, RFC 3448 recomments 0.9
*/
- if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
- ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
+ if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
hctx->ccid3hctx_rtt = r_sample;
- } else
+ else
hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
r_sample / 10;
@@ -508,7 +514,11 @@ static void ccid3_hc_tx_packet_recv(stru
sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
/* Update sending rate (and likely t_ipi, t_nom, and delta) */
- ccid3_hc_tx_update_x(sk);
+ ccid3_hc_tx_update_x(sk, &now);
+
+ /* Update the state if necessary */
+ if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
/* remove all packets older than the one acked from history */
dccp_tx_hist_purge_older(ccid3_tx_hist,
@@ -519,7 +529,6 @@ static void ccid3_hc_tx_packet_recv(stru
*/
sk->sk_write_space(sk);
-
/* Update timeout interval. We use the alternative variant of
* [RFC 3448, 3.1] which sets the upper bound of t_rto to one
* second, as it is suggested for TCP (see RFC 2988, 2.4). */
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -48,8 +48,8 @@
/* In usecs - half the scheduling granularity as per RFC3448 4.6 */
#define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
-/* In seconds */
-#define TFRC_MAX_BACK_OFF_TIME 64
+/* Parameter t_mbi from [RFC 3448, 4.3]: In seconds */
+#define TFRC_t_mbi 64
#define TFRC_SMALLEST_P 40
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 8/10]: Larger initial windows
2006-11-24 16:20 [PATCH 8/10]: Larger initial windows Gerrit Renker
@ 2006-11-26 21:15 ` Ian McDonald
2006-11-27 16:15 ` Eddie Kohler
2006-11-27 17:15 ` Gerrit Renker
2 siblings, 0 replies; 4+ messages in thread
From: Ian McDonald @ 2006-11-26 21:15 UTC (permalink / raw)
To: dccp
On 11/25/06, Gerrit Renker <gerrit@erg.abdn.ac.uk> wrote:
> [CCID 3]: Larger initial windows
>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
--
Ian McDonald
Web: http://wand.net.nz/~iam4
Blog: http://imcdnzl.blogspot.com
WAND Network Research Group
Department of Computer Science
University of Waikato
New Zealand
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 8/10]: Larger initial windows
2006-11-24 16:20 [PATCH 8/10]: Larger initial windows Gerrit Renker
2006-11-26 21:15 ` Ian McDonald
@ 2006-11-27 16:15 ` Eddie Kohler
2006-11-27 17:15 ` Gerrit Renker
2 siblings, 0 replies; 4+ messages in thread
From: Eddie Kohler @ 2006-11-27 16:15 UTC (permalink / raw)
To: dccp
Gerrit, everyone,
Again, the INTENTION I think was for the 2-4 packets per RTT to apply
IMMEDIATELY, because the Request-Response exchange gave you an initial RTT
estimate. But this is just not what RFC 4342 says. When I figure this out
with Sally we will get back to you, and perhaps publish an erratum, allowing
Linux to have the correct behavior while remaining 'standards compliant'.
Eddie
Gerrit Renker wrote:
> [CCID 3]: Larger initial windows
>
> This implements the larger-initial-windows feature for CCID 3, as described
> in section 5 of RFC 4342. When the first feedback packet arrives, the sender
> can send up to 2..4 packets per RTT, instead of just one.
>
> The patch further
> * reduces the number of timestamping calls by passing the timestamp value
> (which is computed in one of the calling functions anyway) as argument
>
> * renames one constant with a very long name into one which is shorter and
> resembles the one in RFC 3448 (t_mbi)
>
> * simplifies some of the min_t/max_t cases where both `x', `y' have the same
> type
>
> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
> ---
> net/dccp/ccids/ccid3.c | 75 +++++++++++++++++++++++++++----------------------
> net/dccp/ccids/ccid3.h | 4 +-
> 2 files changed, 44 insertions(+), 35 deletions(-)
>
> --- a/net/dccp/ccids/ccid3.c
> +++ b/net/dccp/ccids/ccid3.c
> @@ -129,35 +129,42 @@ static inline void ccid3_update_send_tim
> * If X has changed, we also update the scheduled send time t_now,
> * the inter-packet interval t_ipi, and the delta value.
> */
> -static void ccid3_hc_tx_update_x(struct sock *sk)
> +static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
> +
> {
> struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
> const __u32 old_x = hctx->ccid3hctx_x;
>
> DCCP_BUG_ON(hctx->ccid3hctx_rtt = 0);
>
> - /* To avoid large error in calcX */
> - if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
> - hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
> - hctx->ccid3hctx_rtt,
> - hctx->ccid3hctx_p);
> - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
> - 2 * hctx->ccid3hctx_x_recv),
> - (hctx->ccid3hctx_s /
> - TFRC_MAX_BACK_OFF_TIME));
> - } else {
> - struct timeval now;
> + /* Compute X after the first feedback packet has arrived */
> + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
> + /* This implements `Larger Initial Windows' [RFC 4342, sec. 5]
> + * We deviate in that we use `s' instead of `MSS'. */
> + u16 w_init = max( 4 * hctx->ccid3hctx_s,
> + max( 2 * hctx->ccid3hctx_s, 4380));
> + hctx->ccid3hctx_x = usecs_div(w_init, hctx->ccid3hctx_rtt);
> + hctx->ccid3hctx_t_ld = *now;
> +
> + /* To avoid large error in calcX */
> + } else if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
> + hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
> + hctx->ccid3hctx_rtt,
> + hctx->ccid3hctx_p);
> + hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
> + hctx->ccid3hctx_x_recv * 2),
> + hctx->ccid3hctx_s / TFRC_t_mbi );
> +
> + } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >> + hctx->ccid3hctx_rtt) {
> + hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
> + hctx->ccid3hctx_x ) * 2,
> + usecs_div(hctx->ccid3hctx_s,
> + hctx->ccid3hctx_rtt) );
> + hctx->ccid3hctx_t_ld = *now;
> + } else
> + ccid3_pr_debug("Not changing X\n");
>
> - dccp_timestamp(sk, &now);
> - if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >> - hctx->ccid3hctx_rtt) {
> - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
> - hctx->ccid3hctx_x) * 2,
> - usecs_div(hctx->ccid3hctx_s,
> - hctx->ccid3hctx_rtt));
> - hctx->ccid3hctx_t_ld = now;
> - }
> - }
> if(hctx->ccid3hctx_x != old_x)
> ccid3_update_send_time(hctx);
> }
> @@ -185,6 +192,7 @@ static void ccid3_hc_tx_no_feedback_time
> struct sock *sk = (struct sock *)data;
> struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
> unsigned long next_tmout = USEC_PER_SEC / 5;
> + struct timeval now;
>
> bh_lock_sock(sk);
> if (sock_owned_by_user(sk)) {
> @@ -200,10 +208,8 @@ static void ccid3_hc_tx_no_feedback_time
> case TFRC_SSTATE_NO_FBACK:
> /* Halve send rate */
> hctx->ccid3hctx_x /= 2;
> - if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
> - TFRC_MAX_BACK_OFF_TIME))
> - hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
> - TFRC_MAX_BACK_OFF_TIME);
> + if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s / TFRC_t_mbi))
> + hctx->ccid3hctx_x = hctx->ccid3hctx_s / TFRC_t_mbi;
>
> ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
> "bytes/s\n",
> @@ -240,12 +246,13 @@ static void ccid3_hc_tx_no_feedback_time
> if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
> hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
> hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
> - hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
> + hctx->ccid3hctx_s / (2 * TFRC_t_mbi));
> else
> hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
>
> /* Update sending rate */
> - ccid3_hc_tx_update_x(sk);
> + dccp_timestamp(sk, &now);
> + ccid3_hc_tx_update_x(sk, &now);
> }
> /*
> * Schedule no feedback timer to expire in
> @@ -488,10 +495,9 @@ static void ccid3_hc_tx_packet_recv(stru
> *
> * q is a constant, RFC 3448 recomments 0.9
> */
> - if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
> - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
> + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
> hctx->ccid3hctx_rtt = r_sample;
> - } else
> + else
> hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
> r_sample / 10;
>
> @@ -508,7 +514,11 @@ static void ccid3_hc_tx_packet_recv(stru
> sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
>
> /* Update sending rate (and likely t_ipi, t_nom, and delta) */
> - ccid3_hc_tx_update_x(sk);
> + ccid3_hc_tx_update_x(sk, &now);
> +
> + /* Update the state if necessary */
> + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
> + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
>
> /* remove all packets older than the one acked from history */
> dccp_tx_hist_purge_older(ccid3_tx_hist,
> @@ -519,7 +529,6 @@ static void ccid3_hc_tx_packet_recv(stru
> */
> sk->sk_write_space(sk);
>
> -
> /* Update timeout interval. We use the alternative variant of
> * [RFC 3448, 3.1] which sets the upper bound of t_rto to one
> * second, as it is suggested for TCP (see RFC 2988, 2.4). */
> --- a/net/dccp/ccids/ccid3.h
> +++ b/net/dccp/ccids/ccid3.h
> @@ -48,8 +48,8 @@
> /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
> #define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
>
> -/* In seconds */
> -#define TFRC_MAX_BACK_OFF_TIME 64
> +/* Parameter t_mbi from [RFC 3448, 4.3]: In seconds */
> +#define TFRC_t_mbi 64
>
> #define TFRC_SMALLEST_P 40
>
> -
> To unsubscribe from this list: send the line "unsubscribe dccp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 8/10]: Larger initial windows
2006-11-24 16:20 [PATCH 8/10]: Larger initial windows Gerrit Renker
2006-11-26 21:15 ` Ian McDonald
2006-11-27 16:15 ` Eddie Kohler
@ 2006-11-27 17:15 ` Gerrit Renker
2 siblings, 0 replies; 4+ messages in thread
From: Gerrit Renker @ 2006-11-27 17:15 UTC (permalink / raw)
To: dccp
Quoting Eddie Kohler:
| Gerrit, everyone,
|
| Again, the INTENTION I think was for the 2-4 packets per RTT to apply
| IMMEDIATELY, because the Request-Response exchange gave you an initial RTT
| estimate. But this is just not what RFC 4342 says. When I figure this out
| with Sally we will get back to you, and perhaps publish an erratum, allowing
| Linux to have the correct behavior while remaining 'standards compliant'.
see previous reply
|
| Eddie
|
|
| Gerrit Renker wrote:
| > [CCID 3]: Larger initial windows
| >
| > This implements the larger-initial-windows feature for CCID 3, as described
| > in section 5 of RFC 4342. When the first feedback packet arrives, the sender
| > can send up to 2..4 packets per RTT, instead of just one.
| >
| > The patch further
| > * reduces the number of timestamping calls by passing the timestamp value
| > (which is computed in one of the calling functions anyway) as argument
| >
| > * renames one constant with a very long name into one which is shorter and
| > resembles the one in RFC 3448 (t_mbi)
| >
| > * simplifies some of the min_t/max_t cases where both `x', `y' have the same
| > type
| >
| > Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| > ---
| > net/dccp/ccids/ccid3.c | 75 +++++++++++++++++++++++++++----------------------
| > net/dccp/ccids/ccid3.h | 4 +-
| > 2 files changed, 44 insertions(+), 35 deletions(-)
| >
| > --- a/net/dccp/ccids/ccid3.c
| > +++ b/net/dccp/ccids/ccid3.c
| > @@ -129,35 +129,42 @@ static inline void ccid3_update_send_tim
| > * If X has changed, we also update the scheduled send time t_now,
| > * the inter-packet interval t_ipi, and the delta value.
| > */
| > -static void ccid3_hc_tx_update_x(struct sock *sk)
| > +static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now)
| > +
| > {
| > struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
| > const __u32 old_x = hctx->ccid3hctx_x;
| >
| > DCCP_BUG_ON(hctx->ccid3hctx_rtt = 0);
| >
| > - /* To avoid large error in calcX */
| > - if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
| > - hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
| > - hctx->ccid3hctx_rtt,
| > - hctx->ccid3hctx_p);
| > - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
| > - 2 * hctx->ccid3hctx_x_recv),
| > - (hctx->ccid3hctx_s /
| > - TFRC_MAX_BACK_OFF_TIME));
| > - } else {
| > - struct timeval now;
| > + /* Compute X after the first feedback packet has arrived */
| > + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
| > + /* This implements `Larger Initial Windows' [RFC 4342, sec. 5]
| > + * We deviate in that we use `s' instead of `MSS'. */
| > + u16 w_init = max( 4 * hctx->ccid3hctx_s,
| > + max( 2 * hctx->ccid3hctx_s, 4380));
| > + hctx->ccid3hctx_x = usecs_div(w_init, hctx->ccid3hctx_rtt);
| > + hctx->ccid3hctx_t_ld = *now;
| > +
| > + /* To avoid large error in calcX */
| > + } else if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
| > + hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
| > + hctx->ccid3hctx_rtt,
| > + hctx->ccid3hctx_p);
| > + hctx->ccid3hctx_x = max_t(u32, min(hctx->ccid3hctx_x_calc,
| > + hctx->ccid3hctx_x_recv * 2),
| > + hctx->ccid3hctx_s / TFRC_t_mbi );
| > +
| > + } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) >| > + hctx->ccid3hctx_rtt) {
| > + hctx->ccid3hctx_x = max(min(hctx->ccid3hctx_x_recv,
| > + hctx->ccid3hctx_x ) * 2,
| > + usecs_div(hctx->ccid3hctx_s,
| > + hctx->ccid3hctx_rtt) );
| > + hctx->ccid3hctx_t_ld = *now;
| > + } else
| > + ccid3_pr_debug("Not changing X\n");
| >
| > - dccp_timestamp(sk, &now);
| > - if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >| > - hctx->ccid3hctx_rtt) {
| > - hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
| > - hctx->ccid3hctx_x) * 2,
| > - usecs_div(hctx->ccid3hctx_s,
| > - hctx->ccid3hctx_rtt));
| > - hctx->ccid3hctx_t_ld = now;
| > - }
| > - }
| > if(hctx->ccid3hctx_x != old_x)
| > ccid3_update_send_time(hctx);
| > }
| > @@ -185,6 +192,7 @@ static void ccid3_hc_tx_no_feedback_time
| > struct sock *sk = (struct sock *)data;
| > struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
| > unsigned long next_tmout = USEC_PER_SEC / 5;
| > + struct timeval now;
| >
| > bh_lock_sock(sk);
| > if (sock_owned_by_user(sk)) {
| > @@ -200,10 +208,8 @@ static void ccid3_hc_tx_no_feedback_time
| > case TFRC_SSTATE_NO_FBACK:
| > /* Halve send rate */
| > hctx->ccid3hctx_x /= 2;
| > - if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
| > - TFRC_MAX_BACK_OFF_TIME))
| > - hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
| > - TFRC_MAX_BACK_OFF_TIME);
| > + if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s / TFRC_t_mbi))
| > + hctx->ccid3hctx_x = hctx->ccid3hctx_s / TFRC_t_mbi;
| >
| > ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
| > "bytes/s\n",
| > @@ -240,12 +246,13 @@ static void ccid3_hc_tx_no_feedback_time
| > if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
| > hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
| > hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
| > - hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
| > + hctx->ccid3hctx_s / (2 * TFRC_t_mbi));
| > else
| > hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
| >
| > /* Update sending rate */
| > - ccid3_hc_tx_update_x(sk);
| > + dccp_timestamp(sk, &now);
| > + ccid3_hc_tx_update_x(sk, &now);
| > }
| > /*
| > * Schedule no feedback timer to expire in
| > @@ -488,10 +495,9 @@ static void ccid3_hc_tx_packet_recv(stru
| > *
| > * q is a constant, RFC 3448 recomments 0.9
| > */
| > - if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK) {
| > - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
| > + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
| > hctx->ccid3hctx_rtt = r_sample;
| > - } else
| > + else
| > hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
| > r_sample / 10;
| >
| > @@ -508,7 +514,11 @@ static void ccid3_hc_tx_packet_recv(stru
| > sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
| >
| > /* Update sending rate (and likely t_ipi, t_nom, and delta) */
| > - ccid3_hc_tx_update_x(sk);
| > + ccid3_hc_tx_update_x(sk, &now);
| > +
| > + /* Update the state if necessary */
| > + if (hctx->ccid3hctx_state = TFRC_SSTATE_NO_FBACK)
| > + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
| >
| > /* remove all packets older than the one acked from history */
| > dccp_tx_hist_purge_older(ccid3_tx_hist,
| > @@ -519,7 +529,6 @@ static void ccid3_hc_tx_packet_recv(stru
| > */
| > sk->sk_write_space(sk);
| >
| > -
| > /* Update timeout interval. We use the alternative variant of
| > * [RFC 3448, 3.1] which sets the upper bound of t_rto to one
| > * second, as it is suggested for TCP (see RFC 2988, 2.4). */
| > --- a/net/dccp/ccids/ccid3.h
| > +++ b/net/dccp/ccids/ccid3.h
| > @@ -48,8 +48,8 @@
| > /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
| > #define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
| >
| > -/* In seconds */
| > -#define TFRC_MAX_BACK_OFF_TIME 64
| > +/* Parameter t_mbi from [RFC 3448, 4.3]: In seconds */
| > +#define TFRC_t_mbi 64
| >
| > #define TFRC_SMALLEST_P 40
| >
| > -
| > To unsubscribe from this list: send the line "unsubscribe dccp" in
| > the body of a message to majordomo@vger.kernel.org
| > More majordomo info at http://vger.kernel.org/majordomo-info.html
| -
| To unsubscribe from this list: send the line "unsubscribe dccp" in
| the body of a message to majordomo@vger.kernel.org
| More majordomo info at http://vger.kernel.org/majordomo-info.html
|
|
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2006-11-27 17:15 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-11-24 16:20 [PATCH 8/10]: Larger initial windows Gerrit Renker
2006-11-26 21:15 ` Ian McDonald
2006-11-27 16:15 ` Eddie Kohler
2006-11-27 17:15 ` Gerrit Renker
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.