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Diffstat (limited to 'ofproto/pinsched.c')
-rw-r--r--ofproto/pinsched.c86
1 files changed, 30 insertions, 56 deletions
diff --git a/ofproto/pinsched.c b/ofproto/pinsched.c
index 4a939b8bf..57e8e2327 100644
--- a/ofproto/pinsched.c
+++ b/ofproto/pinsched.c
@@ -28,7 +28,9 @@
#include "poll-loop.h"
#include "random.h"
#include "rconn.h"
+#include "sat-math.h"
#include "timeval.h"
+#include "token-bucket.h"
#include "vconn.h"
struct pinqueue {
@@ -39,24 +41,13 @@ struct pinqueue {
};
struct pinsched {
- /* Client-supplied parameters. */
- int rate_limit; /* Packets added to bucket per second. */
- int burst_limit; /* Maximum token bucket size, in packets. */
+ struct token_bucket token_bucket;
/* One queue per physical port. */
struct hmap queues; /* Contains "struct pinqueue"s. */
int n_queued; /* Sum over queues[*].n. */
struct pinqueue *next_txq; /* Next pinqueue check in round-robin. */
- /* Token bucket.
- *
- * It costs 1000 tokens to send a single packet_in message. A single token
- * per message would be more straightforward, but this choice lets us avoid
- * round-off error in refill_bucket()'s calculation of how many tokens to
- * add to the bucket, since no division step is needed. */
- long long int last_fill; /* Time at which we last added tokens. */
- int tokens; /* Current number of tokens. */
-
/* Transmission queue. */
int n_txq; /* No. of packets waiting in rconn for tx. */
@@ -86,6 +77,20 @@ dequeue_packet(struct pinsched *ps, struct pinqueue *q)
return packet;
}
+static void
+adjust_limits(int *rate_limit, int *burst_limit)
+{
+ if (*rate_limit <= 0) {
+ *rate_limit = 1000;
+ }
+ if (*burst_limit <= 0) {
+ *burst_limit = *rate_limit / 4;
+ }
+ if (*burst_limit < 1) {
+ *burst_limit = 1;
+ }
+}
+
/* Destroys 'q' and removes it from 'ps''s set of queues.
* (The caller must ensure that 'q' is empty.) */
static void
@@ -169,30 +174,13 @@ get_tx_packet(struct pinsched *ps)
return packet;
}
-/* Add tokens to the bucket based on elapsed time. */
-static void
-refill_bucket(struct pinsched *ps)
-{
- long long int now = time_msec();
- long long int tokens = (now - ps->last_fill) * ps->rate_limit + ps->tokens;
- if (tokens >= 1000) {
- ps->last_fill = now;
- ps->tokens = MIN(tokens, ps->burst_limit * 1000);
- }
-}
-
/* Attempts to remove enough tokens from 'ps' to transmit a packet. Returns
* true if successful, false otherwise. (In the latter case no tokens are
* removed.) */
static bool
get_token(struct pinsched *ps)
{
- if (ps->tokens >= 1000) {
- ps->tokens -= 1000;
- return true;
- } else {
- return false;
- }
+ return token_bucket_withdraw(&ps->token_bucket, 1000);
}
void
@@ -216,7 +204,7 @@ pinsched_send(struct pinsched *ps, uint16_t port_no,
* otherwise wasted space. */
ofpbuf_trim(packet);
- if (ps->n_queued >= ps->burst_limit) {
+ if (ps->n_queued * 1000 >= ps->token_bucket.burst) {
drop_packet(ps);
}
q = pinqueue_get(ps, port_no);
@@ -235,7 +223,6 @@ pinsched_run(struct pinsched *ps, pinsched_tx_cb *cb, void *aux)
/* Drain some packets out of the bucket if possible, but limit the
* number of iterations to allow other code to get work done too. */
- refill_bucket(ps);
for (i = 0; ps->n_queued && get_token(ps) && i < 50; i++) {
cb(get_tx_packet(ps), aux);
}
@@ -246,14 +233,7 @@ void
pinsched_wait(struct pinsched *ps)
{
if (ps && ps->n_queued) {
- if (ps->tokens >= 1000) {
- /* We can transmit more packets as soon as we're called again. */
- poll_immediate_wake();
- } else {
- /* We have to wait for the bucket to re-fill. We could calculate
- * the exact amount of time here for increased smoothness. */
- poll_timer_wait(TIME_UPDATE_INTERVAL / 2);
- }
+ token_bucket_wait(&ps->token_bucket, 1000);
}
}
@@ -264,16 +244,18 @@ pinsched_create(int rate_limit, int burst_limit)
struct pinsched *ps;
ps = xzalloc(sizeof *ps);
+
+ adjust_limits(&rate_limit, &burst_limit);
+ token_bucket_init(&ps->token_bucket,
+ rate_limit, sat_mul(burst_limit, 1000));
+
hmap_init(&ps->queues);
ps->n_queued = 0;
ps->next_txq = NULL;
- ps->last_fill = time_msec();
- ps->tokens = rate_limit * 1000;
ps->n_txq = 0;
ps->n_normal = 0;
ps->n_limited = 0;
ps->n_queue_dropped = 0;
- pinsched_set_limits(ps, rate_limit, burst_limit);
return ps;
}
@@ -298,24 +280,16 @@ void
pinsched_get_limits(const struct pinsched *ps,
int *rate_limit, int *burst_limit)
{
- *rate_limit = ps->rate_limit;
- *burst_limit = ps->burst_limit;
+ *rate_limit = ps->token_bucket.rate;
+ *burst_limit = ps->token_bucket.burst / 1000;
}
void
pinsched_set_limits(struct pinsched *ps, int rate_limit, int burst_limit)
{
- if (rate_limit <= 0) {
- rate_limit = 1000;
- }
- if (burst_limit <= 0) {
- burst_limit = rate_limit / 4;
- }
- burst_limit = MAX(burst_limit, 1);
- burst_limit = MIN(burst_limit, INT_MAX / 1000);
-
- ps->rate_limit = rate_limit;
- ps->burst_limit = burst_limit;
+ adjust_limits(&rate_limit, &burst_limit);
+ token_bucket_set(&ps->token_bucket,
+ rate_limit, sat_mul(burst_limit, 1000));
while (ps->n_queued > burst_limit) {
drop_packet(ps);
}