diff options
Diffstat (limited to 'ofproto/pinsched.c')
-rw-r--r-- | ofproto/pinsched.c | 86 |
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); } |