This allows clients to do more than just increment a counter. The
following commit will make the first use of that feature.
Signed-off-by: Ben Pfaff <b...@nicira.com>
---
lib/dpif-netdev.c | 75 +++++++++++++++++++++++++++++++++----------
lib/ovs-thread.c | 91 ++++++++++++++++++-----------------------------------
lib/ovs-thread.h | 23 +++++++++++---
3 files changed, 108 insertions(+), 81 deletions(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 54b8f50..268b04d 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -147,10 +147,8 @@ struct dp_netdev {
/* Statistics.
*
- * ovsthread_counter is internally synchronized. */
- struct ovsthread_counter *n_hit; /* Number of flow table matches. */
- struct ovsthread_counter *n_missed; /* Number of flow table misses. */
- struct ovsthread_counter *n_lost; /* Number of misses not passed up. */
+ * ovsthread_stats is internally synchronized. */
+ struct ovsthread_stats stats; /* Contains 'struct dp_netdev_stats *'. */
/* Ports.
*
@@ -170,6 +168,22 @@ static struct dp_netdev_port *dp_netdev_lookup_port(const
struct dp_netdev *dp,
odp_port_t)
OVS_REQ_RDLOCK(dp->port_rwlock);
+enum dp_stat_type {
+ DP_STAT_HIT, /* Packets that matched in the flow table. */
+ DP_STAT_MISS, /* Packets that did not match. */
+ DP_STAT_LOST, /* Packets not passed up to the client. */
+ DP_N_STATS
+};
+
+/* Contained by struct dp_netdev's 'stats' member. */
+struct dp_netdev_stats {
+ struct ovs_mutex mutex; /* Protects 'n'. */
+
+ /* Indexed by DP_STAT_*, protected by 'mutex'. */
+ unsigned long long int n[DP_N_STATS] OVS_GUARDED;
+};
+
+
/* A port in a netdev-based datapath. */
struct dp_netdev_port {
struct hmap_node node; /* Node in dp_netdev's 'ports'. */
@@ -461,9 +475,7 @@ create_dp_netdev(const char *name, const struct dpif_class
*class,
ovs_mutex_unlock(&dp->queue_mutex);
dp->queue_seq = seq_create();
- dp->n_hit = ovsthread_counter_create();
- dp->n_missed = ovsthread_counter_create();
- dp->n_lost = ovsthread_counter_create();
+ ovsthread_stats_init(&dp->stats);
ovs_rwlock_init(&dp->port_rwlock);
hmap_init(&dp->ports);
@@ -532,6 +544,8 @@ dp_netdev_free(struct dp_netdev *dp)
OVS_REQUIRES(dp_netdev_mutex)
{
struct dp_netdev_port *port, *next;
+ struct dp_netdev_stats *bucket;
+ int i;
shash_find_and_delete(&dp_netdevs, dp->name);
@@ -544,9 +558,12 @@ dp_netdev_free(struct dp_netdev *dp)
do_del_port(dp, port->port_no);
}
ovs_rwlock_unlock(&dp->port_rwlock);
- ovsthread_counter_destroy(dp->n_hit);
- ovsthread_counter_destroy(dp->n_missed);
- ovsthread_counter_destroy(dp->n_lost);
+
+ OVSTHREAD_STATS_FOR_EACH_BUCKET (bucket, i, &dp->stats) {
+ ovs_mutex_destroy(&bucket->mutex);
+ free_cacheline(bucket);
+ }
+ ovsthread_stats_destroy(&dp->stats);
dp_netdev_purge_queues(dp);
seq_destroy(dp->queue_seq);
@@ -604,14 +621,21 @@ static int
dpif_netdev_get_stats(const struct dpif *dpif, struct dpif_dp_stats *stats)
{
struct dp_netdev *dp = get_dp_netdev(dpif);
+ struct dp_netdev_stats *bucket;
+ size_t i;
fat_rwlock_rdlock(&dp->cls.rwlock);
stats->n_flows = hmap_count(&dp->flow_table);
fat_rwlock_unlock(&dp->cls.rwlock);
- stats->n_hit = ovsthread_counter_read(dp->n_hit);
- stats->n_missed = ovsthread_counter_read(dp->n_missed);
- stats->n_lost = ovsthread_counter_read(dp->n_lost);
+ stats->n_hit = stats->n_missed = stats->n_lost = 0;
+ OVSTHREAD_STATS_FOR_EACH_BUCKET (bucket, i, &dp->stats) {
+ ovs_mutex_lock(&bucket->mutex);
+ stats->n_hit += bucket->n[DP_STAT_HIT];
+ stats->n_missed += bucket->n[DP_STAT_MISS];
+ stats->n_lost += bucket->n[DP_STAT_LOST];
+ ovs_mutex_unlock(&bucket->mutex);
+ }
stats->n_masks = UINT32_MAX;
stats->n_mask_hit = UINT64_MAX;
@@ -1711,6 +1735,25 @@ dp_netdev_flow_used(struct dp_netdev_flow *netdev_flow,
netdev_flow->tcp_flags |= packet_get_tcp_flags(packet, &netdev_flow->flow);
}
+static void *
+dp_netdev_stats_new_cb(void)
+{
+ struct dp_netdev_stats *bucket = xzalloc_cacheline(sizeof *bucket);
+ ovs_mutex_init(&bucket->mutex);
+ return bucket;
+}
+
+static void
+dp_netdev_count_packet(struct dp_netdev *dp, enum dp_stat_type type)
+{
+ struct dp_netdev_stats *bucket;
+
+ bucket = ovsthread_stats_bucket_get(&dp->stats, dp_netdev_stats_new_cb);
+ ovs_mutex_lock(&bucket->mutex);
+ bucket->n[type]++;
+ ovs_mutex_unlock(&bucket->mutex);
+}
+
static void
dp_netdev_port_input(struct dp_netdev *dp, struct ofpbuf *packet,
struct pkt_metadata *md)
@@ -1736,9 +1779,9 @@ dp_netdev_port_input(struct dp_netdev *dp, struct ofpbuf
*packet,
actions->actions, actions->size);
dp_netdev_actions_unref(actions);
dp_netdev_flow_unref(netdev_flow);
- ovsthread_counter_inc(dp->n_hit, 1);
+ dp_netdev_count_packet(dp, DP_STAT_HIT);
} else {
- ovsthread_counter_inc(dp->n_missed, 1);
+ dp_netdev_count_packet(dp, DP_STAT_MISS);
dp_netdev_output_userspace(dp, packet, DPIF_UC_MISS, &key, NULL);
}
}
@@ -1788,7 +1831,7 @@ dp_netdev_output_userspace(struct dp_netdev *dp, struct
ofpbuf *packet,
error = 0;
} else {
- ovsthread_counter_inc(dp->n_lost, 1);
+ dp_netdev_count_packet(dp, DP_STAT_LOST);
error = ENOBUFS;
}
ovs_mutex_unlock(&dp->queue_mutex);
diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c
index 33b9e08..d313c5a 100644
--- a/lib/ovs-thread.c
+++ b/lib/ovs-thread.c
@@ -377,83 +377,54 @@ may_fork(void)
return !must_not_fork;
}
-/* ovsthread_counter.
- *
- * We implement the counter as an array of N_COUNTERS individual counters, each
- * with its own lock. Each thread uses one of the counters chosen based on a
- * hash of the thread's ID, the idea being that, statistically, different
- * threads will tend to use different counters and therefore avoid
- * interfering with each other.
- *
- * Undoubtedly, better implementations are possible. */
-
-/* Basic counter structure. */
-struct ovsthread_counter__ {
- struct ovs_mutex mutex;
- unsigned long long int value;
-};
-
-/* Pad the basic counter structure to 64 bytes to avoid cache line
- * interference. */
-struct ovsthread_counter {
- struct ovsthread_counter__ c;
- char pad[ROUND_UP(sizeof(struct ovsthread_counter__), 64)
- - sizeof(struct ovsthread_counter__)];
-};
-
-#define N_COUNTERS 16
+/* ovsthread_stats. */
-struct ovsthread_counter *
-ovsthread_counter_create(void)
+void
+ovsthread_stats_init(struct ovsthread_stats *stats)
{
- struct ovsthread_counter *c;
int i;
- c = xmalloc(N_COUNTERS * sizeof *c);
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_init(&c[i].c.mutex);
- c[i].c.value = 0;
+ ovs_mutex_init(&stats->mutex);
+ for (i = 0; i < ARRAY_SIZE(stats->buckets); i++) {
+ stats->buckets[i] = NULL;
}
- return c;
}
void
-ovsthread_counter_destroy(struct ovsthread_counter *c)
+ovsthread_stats_destroy(struct ovsthread_stats *stats)
{
- if (c) {
- int i;
-
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_destroy(&c[i].c.mutex);
- }
- free(c);
- }
+ ovs_mutex_destroy(&stats->mutex);
}
-void
-ovsthread_counter_inc(struct ovsthread_counter *c, unsigned long long int n)
+void *
+ovsthread_stats_bucket_get(struct ovsthread_stats *stats,
+ void *(*new_bucket)(void))
{
- c = &c[hash_int(ovsthread_id_self(), 0) % N_COUNTERS];
-
- ovs_mutex_lock(&c->c.mutex);
- c->c.value += n;
- ovs_mutex_unlock(&c->c.mutex);
+ unsigned int hash = hash_int(ovsthread_id_self(), 0);
+ unsigned int idx = hash & (ARRAY_SIZE(stats->buckets) - 1);
+ void *bucket = stats->buckets[idx];
+ if (!bucket) {
+ ovs_mutex_lock(&stats->mutex);
+ bucket = stats->buckets[idx];
+ if (!bucket) {
+ bucket = stats->buckets[idx] = new_bucket();
+ }
+ ovs_mutex_unlock(&stats->mutex);
+ }
+ return bucket;
}
-unsigned long long int
-ovsthread_counter_read(const struct ovsthread_counter *c)
+size_t
+ovs_thread_stats_next_bucket(const struct ovsthread_stats *stats, size_t i)
{
- unsigned long long int sum;
- int i;
-
- sum = 0;
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_lock(&c[i].c.mutex);
- sum += c[i].c.value;
- ovs_mutex_unlock(&c[i].c.mutex);
+ for (; i < ARRAY_SIZE(stats->buckets); i++) {
+ if (stats->buckets[i]) {
+ break;
+ }
}
- return sum;
+ return i;
}
+
/* Parses /proc/cpuinfo for the total number of physical cores on this system
* across all CPU packages, not counting hyper-threads.
diff --git a/lib/ovs-thread.h b/lib/ovs-thread.h
index f489308..cf1de64 100644
--- a/lib/ovs-thread.h
+++ b/lib/ovs-thread.h
@@ -592,11 +592,24 @@ ovsthread_id_self(void)
*
* Fully thread-safe. */
-struct ovsthread_counter *ovsthread_counter_create(void);
-void ovsthread_counter_destroy(struct ovsthread_counter *);
-void ovsthread_counter_inc(struct ovsthread_counter *, unsigned long long int);
-unsigned long long int ovsthread_counter_read(
- const struct ovsthread_counter *);
+struct ovsthread_stats {
+ struct ovs_mutex mutex;
+ void *volatile buckets[16];
+};
+
+void ovsthread_stats_init(struct ovsthread_stats *);
+void ovsthread_stats_destroy(struct ovsthread_stats *);
+
+void *ovsthread_stats_bucket_get(struct ovsthread_stats *,
+ void *(*new_bucket)(void));
+
+#define OVSTHREAD_STATS_FOR_EACH_BUCKET(BUCKET, IDX, STATS) \
+ for ((IDX) = ovs_thread_stats_next_bucket(STATS, 0); \
+ ((IDX) < ARRAY_SIZE((STATS)->buckets) \
+ ? ((BUCKET) = (STATS)->buckets[IDX], true) \
+ : false); \
+ (IDX) = ovs_thread_stats_next_bucket(STATS, (IDX) + 1))
+size_t ovs_thread_stats_next_bucket(const struct ovsthread_stats *, size_t);
bool single_threaded(void);
--
1.7.10.4
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