X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=datapath%2Fflow_table.c;h=c8bd9d1eddc4d8c663f74585b50e75bc22a49b09;hb=d49fc3ff53c65e4eca9cabd52ac63396746a7ef5;hp=54a2e25e99582b60e5ee6c617986d7a9dd1e8954;hpb=9ac56358dec1a5aa7f4275a42971f55fad1f7f35;p=sliver-openvswitch.git

diff --git a/datapath/flow_table.c b/datapath/flow_table.c
index 54a2e25e9..c8bd9d1ed 100644
--- a/datapath/flow_table.c
+++ b/datapath/flow_table.c
@@ -47,8 +47,13 @@
 #include "vlan.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;
 
@@ -141,7 +146,7 @@ static void flow_free(struct sw_flow *flow)
 {
 	int node;
 
-	kfree((struct sf_flow_acts __force *)flow->sf_acts);
+	kfree((struct sw_flow_actions __force *)flow->sf_acts);
 	for_each_node(node)
 		if (flow->stats[node])
 			kmem_cache_free(flow_stats_cache,
@@ -168,25 +173,6 @@ void ovs_flow_free(struct sw_flow *flow, bool deferred)
 	if (!flow)
 		return;
 
-	if (flow->mask) {
-		struct sw_flow_mask *mask = flow->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);
-			if (deferred)
-				call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
-			else
-				kfree(mask);
-		}
-	}
-
 	if (deferred)
 		call_rcu(&flow->rcu, rcu_free_flow_callback);
 	else
@@ -226,20 +212,83 @@ static struct table_instance *table_instance_alloc(int new_size)
 	return ti;
 }
 
+static void mask_array_rcu_cb(struct rcu_head *rcu)
+{
+	struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
+
+	kfree(ma);
+}
+
+static struct mask_array *tbl_mask_array_alloc(int size)
+{
+	struct mask_array *new;
+
+	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 (old->masks[i])
+				new->masks[new->count++] = old->masks[i];
+		}
+	}
+	rcu_assign_pointer(tbl->mask_array, new);
+
+	if (old)
+		call_rcu(&old->rcu, mask_array_rcu_cb);
+
+	return 0;
+}
+
 int ovs_flow_tbl_init(struct flow_table *table)
 {
 	struct table_instance *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;
 
 	rcu_assign_pointer(table->ti, ti);
-	INIT_LIST_HEAD(&table->mask_list);
+	rcu_assign_pointer(table->mask_array, ma);
 	table->last_rehash = jiffies;
 	table->count = 0;
 	return 0;
+
+free_mask_array:
+	kfree((struct mask_array __force *)table->mask_array);
+free_mask_cache:
+	free_percpu(table->mask_cache);
+	return -ENOMEM;
 }
 
 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
@@ -278,11 +327,15 @@ skip_flows:
 		__table_instance_destroy(ti);
 }
 
-void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred)
+/* No need for locking this function is called from RCU callback or
+ * error path. */
+void ovs_flow_tbl_destroy(struct flow_table *table)
 {
-	struct table_instance *ti = ovsl_dereference(table->ti);
+	struct table_instance *ti = (struct table_instance __force *)table->ti;
 
-	table_instance_destroy(ti, deferred);
+	free_percpu(table->mask_cache);
+	kfree((struct mask_array __force *)table->mask_array);
+	table_instance_destroy(ti, false);
 }
 
 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
@@ -437,7 +490,8 @@ 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,
-					  struct sw_flow_mask *mask)
+					  struct sw_flow_mask *mask,
+					  u32 *n_mask_hit)
 {
 	struct sw_flow *flow;
 	struct hlist_head *head;
@@ -449,6 +503,7 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
 	ovs_flow_mask_key(&masked_key, unmasked, mask);
 	hash = flow_hash(&masked_key, key_start, key_end);
 	head = find_bucket(ti, hash);
+	(*n_mask_hit)++;
 	hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
 		if (flow->mask == mask && flow->hash == hash &&
 		    flow_cmp_masked_key(flow, &masked_key,
@@ -458,41 +513,118 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
 	return NULL;
 }
 
+
+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 sw_flow *flow;
+	int i;
+
+	for (i = 0; i < ma->max; i++) {
+		struct sw_flow_mask *mask;
+
+		mask = rcu_dereference_ovsl(ma->masks[i]);
+		if (mask) {
+			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 *n_mask_hit)
+					  const struct sw_flow_key *key,
+					  u32 skb_hash,
+					  u32 *n_mask_hit)
 {
+	struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
 	struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
-	struct sw_flow_mask *mask;
+	struct mask_cache_entry  *entries, *ce, *del;
 	struct sw_flow *flow;
+	u32 hash = skb_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 */
-			return flow;
+	if (unlikely(!skb_hash)) {
+		u32 __always_unused mask_index;
+
+		return flow_lookup(tbl, ti, ma, key, n_mask_hit, &mask_index);
 	}
-	return NULL;
+
+	del = NULL;
+	entries = this_cpu_ptr(tbl->mask_cache);
+
+	for (seg = 0; seg < MC_HASH_SEGS; seg++) {
+		int index;
+
+		index = hash & (MC_HASH_ENTRIES - 1);
+		ce = &entries[index];
+
+		if (ce->skb_hash == skb_hash) {
+			struct sw_flow_mask *mask;
+			struct sw_flow *flow;
+
+			mask = rcu_dereference_ovsl(ma->masks[ce->mask_index]);
+			if (mask) {
+				flow = masked_flow_lookup(ti, key, mask,
+							  n_mask_hit);
+				if (flow)  /* Found */
+					return flow;
+
+			}
+			del = ce;
+			break;
+		}
+
+		if (!del || (del->skb_hash && !ce->skb_hash) ||
+		    (rcu_dereference_ovsl(ma->masks[del->mask_index]) &&
+		    !rcu_dereference_ovsl(ma->masks[ce->mask_index]))) {
+			del = ce;
+		}
+
+		hash >>= MC_HASH_SHIFT;
+	}
+
+	flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, &del->mask_index);
+	if (flow)
+		del->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 __always_unused index;
 
-	return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
+	n_mask_hit = 0;
+	return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &index);
 }
 
 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++;
+	struct mask_array *ma;
 
-	return num;
+	ma = rcu_dereference_ovsl(table->mask_array);
+	return ma->count;
 }
 
 static struct table_instance *table_instance_expand(struct table_instance *ti)
@@ -500,6 +632,37 @@ static struct table_instance *table_instance_expand(struct table_instance *ti)
 	return table_instance_rehash(ti, ti->n_buckets * 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) {
+			struct mask_array *ma;
+			int i;
+
+			ma = ovsl_dereference(tbl->mask_array);
+			for (i = 0; i < ma->max; i++) {
+				if (mask == ovsl_dereference(ma->masks[i])) {
+					RCU_INIT_POINTER(ma->masks[i], NULL);
+					ma->count--;
+					goto free;
+				}
+			}
+			BUG();
+free:
+			call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
+		}
+	}
+}
+
+/* Must be called with OVS mutex held. */
 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
 {
 	struct table_instance *ti = ovsl_dereference(table->ti);
@@ -507,6 +670,10 @@ void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
 	BUG_ON(table->count == 0);
 	hlist_del_rcu(&flow->hash_node[ti->node_ver]);
 	table->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);
 }
 
 static struct sw_flow_mask *mask_alloc(void)
@@ -534,13 +701,16 @@ 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;
 
-	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;
+	ma = ovsl_dereference(tbl->mask_array);
+	for (i = 0; i < ma->max; i++) {
+		struct sw_flow_mask *t;
+
+		t = ovsl_dereference(ma->masks[i]);
+		if (t && mask_equal(mask, t))
+			return t;
 	}
 
 	return NULL;
@@ -551,15 +721,43 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
 			    struct sw_flow_mask *new)
 {
 	struct sw_flow_mask *mask;
+
 	mask = flow_mask_find(tbl, new);
 	if (!mask) {
+		struct mask_array *ma;
+		int i;
+
 		/* Allocate a new mask if none exsits. */
 		mask = mask_alloc();
 		if (!mask)
 			return -ENOMEM;
+
 		mask->key = new->key;
 		mask->range = new->range;
-		list_add_rcu(&mask->list, &tbl->mask_list);
+
+		/* Add mask to mask-list. */
+		ma = ovsl_dereference(tbl->mask_array);
+		if (ma->count >= ma->max) {
+			int err;
+
+			err = tbl_mask_array_realloc(tbl, ma->max +
+							MASK_ARRAY_SIZE_MIN);
+			if (err) {
+				kfree(mask);
+				return err;
+			}
+			ma = ovsl_dereference(tbl->mask_array);
+		}
+		for (i = 0; i < ma->max; i++) {
+			const struct sw_flow_mask *t;
+
+			t = ovsl_dereference(ma->masks[i]);
+			if (!t) {
+				rcu_assign_pointer(ma->masks[i], mask);
+				ma->count++;
+				break;
+			}
+		}
 	} else {
 		BUG_ON(!mask->ref_count);
 		mask->ref_count++;
@@ -569,6 +767,7 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
 	return 0;
 }
 
+/* Must be called with OVS mutex held. */
 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
 			struct sw_flow_mask *mask)
 {