From: Ben Pfaff Date: Tue, 23 Nov 2010 21:20:17 +0000 (-0800) Subject: pinsched: Use hmap instead of port_array. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=531edfbb427fd7f3287d8e6412b115e2cf6dc558;p=openvswitch pinsched: Use hmap instead of port_array. This is the last remaining use of port_array in the tree. It wasn't really taking advantage of any of the special features of port_arrays, so it's better to save some time and memory by using an hmap instead. (In addition, OpenFlow 1.1, which we may eventually want to support, has changed from 16-bit to 32-bit port numbers, which would require the port_array code to be rewritten anyhow.) --- diff --git a/ofproto/pinsched.c b/ofproto/pinsched.c index 29bd65e5..dc835585 100644 --- a/ofproto/pinsched.c +++ b/ofproto/pinsched.c @@ -21,10 +21,10 @@ #include #include #include +#include "hmap.h" #include "ofpbuf.h" #include "openflow/openflow.h" #include "poll-loop.h" -#include "port-array.h" #include "random.h" #include "rconn.h" #include "status.h" @@ -32,6 +32,8 @@ #include "vconn.h" struct pinqueue { + struct hmap_node node; /* In struct pinsched's 'queues' hmap. */ + uint16_t port_no; /* Port number. */ struct list packets; /* Contains "struct ofpbuf"s. */ int n; /* Number of packets in 'packets'. */ }; @@ -42,9 +44,9 @@ struct pinsched { int burst_limit; /* Maximum token bucket size, in packets. */ /* One queue per physical port. */ - struct port_array queues; /* Array of "struct pinqueue *"s. */ + struct hmap queues; /* Contains "struct pinqueue"s. */ int n_queued; /* Sum over queues[*].n. */ - unsigned int last_tx_port; /* Last port checked in round-robin. */ + struct pinqueue *next_txq; /* Next pinqueue check in round-robin. */ /* Token bucket. * @@ -67,35 +69,68 @@ struct pinsched { struct status_category *ss_cat; }; +static void +advance_txq(struct pinsched *ps) +{ + struct hmap_node *next; + + next = (ps->next_txq + ? hmap_next(&ps->queues, &ps->next_txq->node) + : hmap_first(&ps->queues)); + ps->next_txq = next ? CONTAINER_OF(next, struct pinqueue, node) : NULL; +} + static struct ofpbuf * -dequeue_packet(struct pinsched *ps, struct pinqueue *q, unsigned int port_no) +dequeue_packet(struct pinsched *ps, struct pinqueue *q) { struct ofpbuf *packet = ofpbuf_from_list(list_pop_front(&q->packets)); - if (--q->n == 0) { - free(q); - port_array_delete(&ps->queues, port_no); - } + q->n--; ps->n_queued--; return packet; } +/* Destroys 'q' and removes it from 'ps''s set of queues. + * (The caller must ensure that 'q' is empty.) */ +static void +pinqueue_destroy(struct pinsched *ps, struct pinqueue *q) +{ + hmap_remove(&ps->queues, &q->node); + free(q); +} + +static struct pinqueue * +pinqueue_get(struct pinsched *ps, uint16_t port_no) +{ + uint32_t hash = hash_int(port_no, 0); + struct pinqueue *q; + + HMAP_FOR_EACH_IN_BUCKET (q, node, hash, &ps->queues) { + if (port_no == q->port_no) { + return q; + } + } + + q = xmalloc(sizeof *q); + hmap_insert(&ps->queues, &q->node, hash); + q->port_no = port_no; + list_init(&q->packets); + q->n = 0; + return q; +} + /* Drop a packet from the longest queue in 'ps'. */ static void drop_packet(struct pinsched *ps) { struct pinqueue *longest; /* Queue currently selected as longest. */ int n_longest; /* # of queues of same length as 'longest'. */ - unsigned int longest_port_no; - unsigned int port_no; struct pinqueue *q; ps->n_queue_dropped++; - longest = port_array_first(&ps->queues, &port_no); - longest_port_no = port_no; - n_longest = 1; - while ((q = port_array_next(&ps->queues, &port_no)) != NULL) { - if (longest->n < q->n) { + longest = NULL; + HMAP_FOR_EACH (q, node, &ps->queues) { + if (!longest || longest->n < q->n) { longest = q; n_longest = 1; } else if (longest->n == q->n) { @@ -105,24 +140,36 @@ drop_packet(struct pinsched *ps) * distribution (Knuth algorithm 3.4.2R). */ if (!random_range(n_longest)) { longest = q; - longest_port_no = port_no; } } } /* FIXME: do we want to pop the tail instead? */ - ofpbuf_delete(dequeue_packet(ps, longest, longest_port_no)); + ofpbuf_delete(dequeue_packet(ps, longest)); + if (longest->n == 0) { + pinqueue_destroy(ps, longest); + } } /* Remove and return the next packet to transmit (in round-robin order). */ static struct ofpbuf * get_tx_packet(struct pinsched *ps) { - struct pinqueue *q = port_array_next(&ps->queues, &ps->last_tx_port); - if (!q) { - q = port_array_first(&ps->queues, &ps->last_tx_port); + struct ofpbuf *packet; + struct pinqueue *q; + + if (!ps->next_txq) { + advance_txq(ps); + } + + q = ps->next_txq; + packet = dequeue_packet(ps, q); + advance_txq(ps); + if (q->n == 0) { + pinqueue_destroy(ps, q); } - return dequeue_packet(ps, q, ps->last_tx_port); + + return packet; } /* Add tokens to the bucket based on elapsed time. */ @@ -175,13 +222,7 @@ pinsched_send(struct pinsched *ps, uint16_t port_no, if (ps->n_queued >= ps->burst_limit) { drop_packet(ps); } - q = port_array_get(&ps->queues, port_no); - if (!q) { - q = xmalloc(sizeof *q); - list_init(&q->packets); - q->n = 0; - port_array_set(&ps->queues, port_no, q); - } + q = pinqueue_get(ps, port_no); list_push_back(&q->packets, &packet->list_node); q->n++; ps->n_queued++; @@ -236,9 +277,9 @@ pinsched_create(int rate_limit, int burst_limit, struct switch_status *ss) struct pinsched *ps; ps = xzalloc(sizeof *ps); - port_array_init(&ps->queues); + hmap_init(&ps->queues); ps->n_queued = 0; - ps->last_tx_port = PORT_ARRAY_SIZE; + ps->next_txq = NULL; ps->last_fill = time_msec(); ps->tokens = rate_limit * 100; ps->n_txq = 0; @@ -259,14 +300,14 @@ void pinsched_destroy(struct pinsched *ps) { if (ps) { - struct pinqueue *queue; - unsigned int port_no; + struct pinqueue *q, *next; - PORT_ARRAY_FOR_EACH (queue, &ps->queues, port_no) { - ofpbuf_list_delete(&queue->packets); - free(queue); + HMAP_FOR_EACH_SAFE (q, next, node, &ps->queues) { + hmap_remove(&ps->queues, &q->node); + ofpbuf_list_delete(&q->packets); + free(q); } - port_array_destroy(&ps->queues); + hmap_destroy(&ps->queues); switch_status_unregister(ps->ss_cat); free(ps); }