summaryrefslogtreecommitdiff
path: root/net/openvswitch/flow_table.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/openvswitch/flow_table.c')
-rw-r--r--net/openvswitch/flow_table.c381
1 files changed, 304 insertions, 77 deletions
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index cf3582c5ed70..5904e93e5765 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -34,8 +34,13 @@
#include <net/ndisc.h>
#define TBL_MIN_BUCKETS 1024
+#define MASK_ARRAY_SIZE_MIN 16
#define REHASH_INTERVAL (10 * 60 * HZ)
+#define MC_HASH_SHIFT 8
+#define MC_HASH_ENTRIES (1u << MC_HASH_SHIFT)
+#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT)
+
static struct kmem_cache *flow_cache;
struct kmem_cache *flow_stats_cache __read_mostly;
@@ -164,14 +169,133 @@ static struct table_instance *table_instance_alloc(int new_size)
return ti;
}
+static struct mask_array *tbl_mask_array_alloc(int size)
+{
+ struct mask_array *new;
+
+ size = max(MASK_ARRAY_SIZE_MIN, size);
+ new = kzalloc(sizeof(struct mask_array) +
+ sizeof(struct sw_flow_mask *) * size, GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ new->count = 0;
+ new->max = size;
+
+ return new;
+}
+
+static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
+{
+ struct mask_array *old;
+ struct mask_array *new;
+
+ new = tbl_mask_array_alloc(size);
+ if (!new)
+ return -ENOMEM;
+
+ old = ovsl_dereference(tbl->mask_array);
+ if (old) {
+ int i;
+
+ for (i = 0; i < old->max; i++) {
+ if (ovsl_dereference(old->masks[i]))
+ new->masks[new->count++] = old->masks[i];
+ }
+ }
+
+ rcu_assign_pointer(tbl->mask_array, new);
+ kfree_rcu(old, rcu);
+
+ return 0;
+}
+
+static int tbl_mask_array_add_mask(struct flow_table *tbl,
+ struct sw_flow_mask *new)
+{
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int err, ma_count = READ_ONCE(ma->count);
+
+ if (ma_count >= ma->max) {
+ err = tbl_mask_array_realloc(tbl, ma->max +
+ MASK_ARRAY_SIZE_MIN);
+ if (err)
+ return err;
+
+ ma = ovsl_dereference(tbl->mask_array);
+ }
+
+ BUG_ON(ovsl_dereference(ma->masks[ma_count]));
+
+ rcu_assign_pointer(ma->masks[ma_count], new);
+ WRITE_ONCE(ma->count, ma_count +1);
+
+ return 0;
+}
+
+static void tbl_mask_array_del_mask(struct flow_table *tbl,
+ struct sw_flow_mask *mask)
+{
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int i, ma_count = READ_ONCE(ma->count);
+
+ /* Remove the deleted mask pointers from the array */
+ for (i = 0; i < ma_count; i++) {
+ if (mask == ovsl_dereference(ma->masks[i]))
+ goto found;
+ }
+
+ BUG();
+ return;
+
+found:
+ WRITE_ONCE(ma->count, ma_count -1);
+
+ rcu_assign_pointer(ma->masks[i], ma->masks[ma_count -1]);
+ RCU_INIT_POINTER(ma->masks[ma_count -1], NULL);
+
+ kfree_rcu(mask, rcu);
+
+ /* Shrink the mask array if necessary. */
+ if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
+ ma_count <= (ma->max / 3))
+ tbl_mask_array_realloc(tbl, ma->max / 2);
+}
+
+/* Remove 'mask' from the mask list, if it is not needed any more. */
+static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
+{
+ if (mask) {
+ /* ovs-lock is required to protect mask-refcount and
+ * mask list.
+ */
+ ASSERT_OVSL();
+ BUG_ON(!mask->ref_count);
+ mask->ref_count--;
+
+ if (!mask->ref_count)
+ tbl_mask_array_del_mask(tbl, mask);
+ }
+}
+
int ovs_flow_tbl_init(struct flow_table *table)
{
struct table_instance *ti, *ufid_ti;
+ struct mask_array *ma;
- ti = table_instance_alloc(TBL_MIN_BUCKETS);
+ table->mask_cache = __alloc_percpu(sizeof(struct mask_cache_entry) *
+ MC_HASH_ENTRIES,
+ __alignof__(struct mask_cache_entry));
+ if (!table->mask_cache)
+ return -ENOMEM;
+ ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
+ if (!ma)
+ goto free_mask_cache;
+
+ ti = table_instance_alloc(TBL_MIN_BUCKETS);
if (!ti)
- return -ENOMEM;
+ goto free_mask_array;
ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
if (!ufid_ti)
@@ -179,7 +303,7 @@ int ovs_flow_tbl_init(struct flow_table *table)
rcu_assign_pointer(table->ti, ti);
rcu_assign_pointer(table->ufid_ti, ufid_ti);
- INIT_LIST_HEAD(&table->mask_list);
+ rcu_assign_pointer(table->mask_array, ma);
table->last_rehash = jiffies;
table->count = 0;
table->ufid_count = 0;
@@ -187,6 +311,10 @@ int ovs_flow_tbl_init(struct flow_table *table)
free_ti:
__table_instance_destroy(ti);
+free_mask_array:
+ kfree(ma);
+free_mask_cache:
+ free_percpu(table->mask_cache);
return -ENOMEM;
}
@@ -197,7 +325,28 @@ static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
__table_instance_destroy(ti);
}
-static void table_instance_destroy(struct table_instance *ti,
+static void table_instance_flow_free(struct flow_table *table,
+ struct table_instance *ti,
+ struct table_instance *ufid_ti,
+ struct sw_flow *flow,
+ bool count)
+{
+ hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
+ if (count)
+ table->count--;
+
+ if (ovs_identifier_is_ufid(&flow->id)) {
+ hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
+
+ if (count)
+ table->ufid_count--;
+ }
+
+ flow_mask_remove(table, flow->mask);
+}
+
+static void table_instance_destroy(struct flow_table *table,
+ struct table_instance *ti,
struct table_instance *ufid_ti,
bool deferred)
{
@@ -214,13 +363,12 @@ static void table_instance_destroy(struct table_instance *ti,
struct sw_flow *flow;
struct hlist_head *head = &ti->buckets[i];
struct hlist_node *n;
- int ver = ti->node_ver;
- int ufid_ver = ufid_ti->node_ver;
- hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) {
- hlist_del_rcu(&flow->flow_table.node[ver]);
- if (ovs_identifier_is_ufid(&flow->id))
- hlist_del_rcu(&flow->ufid_table.node[ufid_ver]);
+ hlist_for_each_entry_safe(flow, n, head,
+ flow_table.node[ti->node_ver]) {
+
+ table_instance_flow_free(table, ti, ufid_ti,
+ flow, false);
ovs_flow_free(flow, deferred);
}
}
@@ -243,7 +391,9 @@ void ovs_flow_tbl_destroy(struct flow_table *table)
struct table_instance *ti = rcu_dereference_raw(table->ti);
struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
- table_instance_destroy(ti, ufid_ti, false);
+ free_percpu(table->mask_cache);
+ kfree_rcu(rcu_dereference_raw(table->mask_array), rcu);
+ table_instance_destroy(table, ti, ufid_ti, false);
}
struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
@@ -359,7 +509,7 @@ int ovs_flow_tbl_flush(struct flow_table *flow_table)
flow_table->count = 0;
flow_table->ufid_count = 0;
- table_instance_destroy(old_ti, old_ufid_ti, true);
+ table_instance_destroy(flow_table, old_ti, old_ufid_ti, true);
return 0;
err_free_ti:
@@ -370,13 +520,10 @@ err_free_ti:
static u32 flow_hash(const struct sw_flow_key *key,
const struct sw_flow_key_range *range)
{
- int key_start = range->start;
- int key_end = range->end;
- const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
- int hash_u32s = (key_end - key_start) >> 2;
+ const u32 *hash_key = (const u32 *)((const u8 *)key + range->start);
/* Make sure number of hash bytes are multiple of u32. */
- BUILD_BUG_ON(sizeof(long) % sizeof(u32));
+ int hash_u32s = range_n_bytes(range) >> 2;
return jhash2(hash_key, hash_u32s, 0);
}
@@ -425,7 +572,8 @@ static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
const struct sw_flow_key *unmasked,
- const struct sw_flow_mask *mask)
+ const struct sw_flow_mask *mask,
+ u32 *n_mask_hit)
{
struct sw_flow *flow;
struct hlist_head *head;
@@ -435,6 +583,8 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
ovs_flow_mask_key(&masked_key, unmasked, false, mask);
hash = flow_hash(&masked_key, &mask->range);
head = find_bucket(ti, hash);
+ (*n_mask_hit)++;
+
hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
if (flow->mask == mask && flow->flow_table.hash == hash &&
flow_cmp_masked_key(flow, &masked_key, &mask->range))
@@ -443,46 +593,147 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
return NULL;
}
-struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
- const struct sw_flow_key *key,
- u32 *n_mask_hit)
+/* Flow lookup does full lookup on flow table. It starts with
+ * mask from index passed in *index.
+ */
+static struct sw_flow *flow_lookup(struct flow_table *tbl,
+ struct table_instance *ti,
+ struct mask_array *ma,
+ const struct sw_flow_key *key,
+ u32 *n_mask_hit,
+ u32 *index)
{
- struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
+ struct sw_flow *flow;
struct sw_flow_mask *mask;
+ int i;
+
+ if (likely(*index < ma->max)) {
+ mask = rcu_dereference_ovsl(ma->masks[*index]);
+ if (mask) {
+ flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
+ if (flow)
+ return flow;
+ }
+ }
+
+ for (i = 0; i < ma->max; i++) {
+
+ if (i == *index)
+ continue;
+
+ mask = rcu_dereference_ovsl(ma->masks[i]);
+ if (unlikely(!mask))
+ break;
+
+ flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
+ if (flow) { /* Found */
+ *index = i;
+ return flow;
+ }
+ }
+
+ return NULL;
+}
+
+/*
+ * mask_cache maps flow to probable mask. This cache is not tightly
+ * coupled cache, It means updates to mask list can result in inconsistent
+ * cache entry in mask cache.
+ * This is per cpu cache and is divided in MC_HASH_SEGS segments.
+ * In case of a hash collision the entry is hashed in next segment.
+ * */
+struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
+ const struct sw_flow_key *key,
+ u32 skb_hash,
+ u32 *n_mask_hit)
+{
+ struct mask_array *ma = rcu_dereference(tbl->mask_array);
+ struct table_instance *ti = rcu_dereference(tbl->ti);
+ struct mask_cache_entry *entries, *ce;
struct sw_flow *flow;
+ u32 hash;
+ int seg;
*n_mask_hit = 0;
- list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
- (*n_mask_hit)++;
- flow = masked_flow_lookup(ti, key, mask);
- if (flow) /* Found */
+ if (unlikely(!skb_hash)) {
+ u32 mask_index = 0;
+
+ return flow_lookup(tbl, ti, ma, key, n_mask_hit, &mask_index);
+ }
+
+ /* Pre and post recirulation flows usually have the same skb_hash
+ * value. To avoid hash collisions, rehash the 'skb_hash' with
+ * 'recirc_id'. */
+ if (key->recirc_id)
+ skb_hash = jhash_1word(skb_hash, key->recirc_id);
+
+ ce = NULL;
+ hash = skb_hash;
+ entries = this_cpu_ptr(tbl->mask_cache);
+
+ /* Find the cache entry 'ce' to operate on. */
+ for (seg = 0; seg < MC_HASH_SEGS; seg++) {
+ int index = hash & (MC_HASH_ENTRIES - 1);
+ struct mask_cache_entry *e;
+
+ e = &entries[index];
+ if (e->skb_hash == skb_hash) {
+ flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
+ &e->mask_index);
+ if (!flow)
+ e->skb_hash = 0;
return flow;
+ }
+
+ if (!ce || e->skb_hash < ce->skb_hash)
+ ce = e; /* A better replacement cache candidate. */
+
+ hash >>= MC_HASH_SHIFT;
}
- return NULL;
+
+ /* Cache miss, do full lookup. */
+ flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, &ce->mask_index);
+ if (flow)
+ ce->skb_hash = skb_hash;
+
+ return flow;
}
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
const struct sw_flow_key *key)
{
+ struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
+ struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
u32 __always_unused n_mask_hit;
+ u32 index = 0;
- return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
+ return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &index);
}
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
const struct sw_flow_match *match)
{
- struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
- struct sw_flow_mask *mask;
- struct sw_flow *flow;
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int i;
/* Always called under ovs-mutex. */
- list_for_each_entry(mask, &tbl->mask_list, list) {
- flow = masked_flow_lookup(ti, match->key, mask);
+ for (i = 0; i < ma->max; i++) {
+ struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
+ u32 __always_unused n_mask_hit;
+ struct sw_flow_mask *mask;
+ struct sw_flow *flow;
+
+ mask = ovsl_dereference(ma->masks[i]);
+ if (!mask)
+ continue;
+
+ flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
if (flow && ovs_identifier_is_key(&flow->id) &&
- ovs_flow_cmp_unmasked_key(flow, match))
+ ovs_flow_cmp_unmasked_key(flow, match)) {
return flow;
+ }
}
+
return NULL;
}
@@ -528,13 +779,8 @@ struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
int ovs_flow_tbl_num_masks(const struct flow_table *table)
{
- struct sw_flow_mask *mask;
- int num = 0;
-
- list_for_each_entry(mask, &table->mask_list, list)
- num++;
-
- return num;
+ struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
+ return READ_ONCE(ma->count);
}
static struct table_instance *table_instance_expand(struct table_instance *ti,
@@ -543,24 +789,6 @@ static struct table_instance *table_instance_expand(struct table_instance *ti,
return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
}
-/* Remove 'mask' from the mask list, if it is not needed any more. */
-static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
-{
- if (mask) {
- /* ovs-lock is required to protect mask-refcount and
- * mask list.
- */
- ASSERT_OVSL();
- BUG_ON(!mask->ref_count);
- mask->ref_count--;
-
- if (!mask->ref_count) {
- list_del_rcu(&mask->list);
- kfree_rcu(mask, rcu);
- }
- }
-}
-
/* Must be called with OVS mutex held. */
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
{
@@ -568,17 +796,7 @@ void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
BUG_ON(table->count == 0);
- hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
- table->count--;
- if (ovs_identifier_is_ufid(&flow->id)) {
- hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
- table->ufid_count--;
- }
-
- /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be
- * accessible as long as the RCU read lock is held.
- */
- flow_mask_remove(table, flow->mask);
+ table_instance_flow_free(table, ti, ufid_ti, flow, true);
}
static struct sw_flow_mask *mask_alloc(void)
@@ -606,13 +824,16 @@ static bool mask_equal(const struct sw_flow_mask *a,
static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
const struct sw_flow_mask *mask)
{
- struct list_head *ml;
+ struct mask_array *ma;
+ int i;
+
+ ma = ovsl_dereference(tbl->mask_array);
+ for (i = 0; i < ma->max; i++) {
+ struct sw_flow_mask *t;
+ t = ovsl_dereference(ma->masks[i]);
- list_for_each(ml, &tbl->mask_list) {
- struct sw_flow_mask *m;
- m = container_of(ml, struct sw_flow_mask, list);
- if (mask_equal(mask, m))
- return m;
+ if (t && mask_equal(mask, t))
+ return t;
}
return NULL;
@@ -623,6 +844,7 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
const struct sw_flow_mask *new)
{
struct sw_flow_mask *mask;
+
mask = flow_mask_find(tbl, new);
if (!mask) {
/* Allocate a new mask if none exsits. */
@@ -631,7 +853,12 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
return -ENOMEM;
mask->key = new->key;
mask->range = new->range;
- list_add_rcu(&mask->list, &tbl->mask_list);
+
+ /* Add mask to mask-list. */
+ if (tbl_mask_array_add_mask(tbl, mask)) {
+ kfree(mask);
+ return -ENOMEM;
+ }
} else {
BUG_ON(!mask->ref_count);
mask->ref_count++;