* [PATCH net-next v4 1/2] net: openvswitch: add masks cache hit counter
2020-07-31 12:20 [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
@ 2020-07-31 12:20 ` Eelco Chaudron
2020-07-31 12:21 ` [PATCH net-next v4 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
2020-08-03 22:18 ` [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Eelco Chaudron @ 2020-07-31 12:20 UTC (permalink / raw)
To: netdev; +Cc: davem, dev, kuba, pabeni, pshelar, fw, xiangxia.m.yue
Add a counter that counts the number of masks cache hits, and
export it through the megaflow netlink statistics.
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
include/uapi/linux/openvswitch.h | 2 +-
net/openvswitch/datapath.c | 5 ++++-
net/openvswitch/datapath.h | 3 +++
net/openvswitch/flow_table.c | 19 ++++++++++++++-----
net/openvswitch/flow_table.h | 3 ++-
5 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 9b14519e74d9..7cb76e5ca7cf 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -102,8 +102,8 @@ struct ovs_dp_megaflow_stats {
__u64 n_mask_hit; /* Number of masks used for flow lookups. */
__u32 n_masks; /* Number of masks for the datapath. */
__u32 pad0; /* Pad for future expension. */
+ __u64 n_cache_hit; /* Number of cache matches for flow lookups. */
__u64 pad1; /* Pad for future expension. */
- __u64 pad2; /* Pad for future expension. */
};
struct ovs_vport_stats {
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 95805f0e27bd..a54df1fe3ec4 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -225,13 +225,14 @@ void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key)
struct dp_stats_percpu *stats;
u64 *stats_counter;
u32 n_mask_hit;
+ u32 n_cache_hit;
int error;
stats = this_cpu_ptr(dp->stats_percpu);
/* Look up flow. */
flow = ovs_flow_tbl_lookup_stats(&dp->table, key, skb_get_hash(skb),
- &n_mask_hit);
+ &n_mask_hit, &n_cache_hit);
if (unlikely(!flow)) {
struct dp_upcall_info upcall;
@@ -262,6 +263,7 @@ void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key)
u64_stats_update_begin(&stats->syncp);
(*stats_counter)++;
stats->n_mask_hit += n_mask_hit;
+ stats->n_cache_hit += n_cache_hit;
u64_stats_update_end(&stats->syncp);
}
@@ -699,6 +701,7 @@ static void get_dp_stats(const struct datapath *dp, struct ovs_dp_stats *stats,
stats->n_missed += local_stats.n_missed;
stats->n_lost += local_stats.n_lost;
mega_stats->n_mask_hit += local_stats.n_mask_hit;
+ mega_stats->n_cache_hit += local_stats.n_cache_hit;
}
}
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
index 697a2354194b..86d78613edb4 100644
--- a/net/openvswitch/datapath.h
+++ b/net/openvswitch/datapath.h
@@ -38,12 +38,15 @@
* @n_mask_hit: Number of masks looked up for flow match.
* @n_mask_hit / (@n_hit + @n_missed) will be the average masks looked
* up per packet.
+ * @n_cache_hit: The number of received packets that had their mask found using
+ * the mask cache.
*/
struct dp_stats_percpu {
u64 n_hit;
u64 n_missed;
u64 n_lost;
u64 n_mask_hit;
+ u64 n_cache_hit;
struct u64_stats_sync syncp;
};
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index af22c9ee28dd..a5912ea05352 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -667,6 +667,7 @@ static struct sw_flow *flow_lookup(struct flow_table *tbl,
struct mask_array *ma,
const struct sw_flow_key *key,
u32 *n_mask_hit,
+ u32 *n_cache_hit,
u32 *index)
{
u64 *usage_counters = this_cpu_ptr(ma->masks_usage_cntr);
@@ -682,6 +683,7 @@ static struct sw_flow *flow_lookup(struct flow_table *tbl,
u64_stats_update_begin(&ma->syncp);
usage_counters[*index]++;
u64_stats_update_end(&ma->syncp);
+ (*n_cache_hit)++;
return flow;
}
}
@@ -719,7 +721,8 @@ static struct sw_flow *flow_lookup(struct flow_table *tbl,
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)
+ u32 *n_mask_hit,
+ u32 *n_cache_hit)
{
struct mask_array *ma = rcu_dereference(tbl->mask_array);
struct table_instance *ti = rcu_dereference(tbl->ti);
@@ -729,10 +732,13 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
int seg;
*n_mask_hit = 0;
+ *n_cache_hit = 0;
if (unlikely(!skb_hash)) {
u32 mask_index = 0;
+ u32 cache = 0;
- return flow_lookup(tbl, ti, ma, key, n_mask_hit, &mask_index);
+ return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
+ &mask_index);
}
/* Pre and post recirulation flows usually have the same skb_hash
@@ -753,7 +759,7 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
e = &entries[index];
if (e->skb_hash == skb_hash) {
flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
- &e->mask_index);
+ n_cache_hit, &e->mask_index);
if (!flow)
e->skb_hash = 0;
return flow;
@@ -766,10 +772,12 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
}
/* Cache miss, do full lookup. */
- flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, &ce->mask_index);
+ flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
+ &ce->mask_index);
if (flow)
ce->skb_hash = skb_hash;
+ *n_cache_hit = 0;
return flow;
}
@@ -779,9 +787,10 @@ struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
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 n_cache_hit;
u32 index = 0;
- return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &index);
+ return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
}
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h
index 1f664b050e3b..325e939371d8 100644
--- a/net/openvswitch/flow_table.h
+++ b/net/openvswitch/flow_table.h
@@ -82,7 +82,8 @@ struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *table,
struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *,
const struct sw_flow_key *,
u32 skb_hash,
- u32 *n_mask_hit);
+ u32 *n_mask_hit,
+ u32 *n_cache_hit);
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *,
const struct sw_flow_key *);
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH net-next v4 2/2] net: openvswitch: make masks cache size configurable
2020-07-31 12:20 [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
2020-07-31 12:20 ` [PATCH net-next v4 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
@ 2020-07-31 12:21 ` Eelco Chaudron
2020-08-03 22:18 ` [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Eelco Chaudron @ 2020-07-31 12:21 UTC (permalink / raw)
To: netdev; +Cc: davem, dev, kuba, pabeni, pshelar, fw, xiangxia.m.yue
This patch makes the masks cache size configurable, or with
a size of 0, disable it.
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
Changes in v4:
- Remove null check before calling free_percpu()
- Make ovs_dp_change() return appropriate error codes
Changes in v3:
- Use is_power_of_2() function
- Use array_size() function
- Fix remaining sparse errors
Changes in v2:
- Fix sparse warnings
- Fix netlink policy items reported by Florian Westphal
include/uapi/linux/openvswitch.h | 1
net/openvswitch/datapath.c | 17 ++++++
net/openvswitch/flow_table.c | 101 +++++++++++++++++++++++++++++++++-----
net/openvswitch/flow_table.h | 10 +++-
4 files changed, 115 insertions(+), 14 deletions(-)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 7cb76e5ca7cf..8300cc29dec8 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -86,6 +86,7 @@ enum ovs_datapath_attr {
OVS_DP_ATTR_MEGAFLOW_STATS, /* struct ovs_dp_megaflow_stats */
OVS_DP_ATTR_USER_FEATURES, /* OVS_DP_F_* */
OVS_DP_ATTR_PAD,
+ OVS_DP_ATTR_MASKS_CACHE_SIZE,
__OVS_DP_ATTR_MAX
};
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index a54df1fe3ec4..b58604eca032 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1498,6 +1498,7 @@ static size_t ovs_dp_cmd_msg_size(void)
msgsize += nla_total_size_64bit(sizeof(struct ovs_dp_stats));
msgsize += nla_total_size_64bit(sizeof(struct ovs_dp_megaflow_stats));
msgsize += nla_total_size(sizeof(u32)); /* OVS_DP_ATTR_USER_FEATURES */
+ msgsize += nla_total_size(sizeof(u32)); /* OVS_DP_ATTR_MASKS_CACHE_SIZE */
return msgsize;
}
@@ -1535,6 +1536,10 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
if (nla_put_u32(skb, OVS_DP_ATTR_USER_FEATURES, dp->user_features))
goto nla_put_failure;
+ if (nla_put_u32(skb, OVS_DP_ATTR_MASKS_CACHE_SIZE,
+ ovs_flow_tbl_masks_cache_size(&dp->table)))
+ goto nla_put_failure;
+
genlmsg_end(skb, ovs_header);
return 0;
@@ -1599,6 +1604,16 @@ static int ovs_dp_change(struct datapath *dp, struct nlattr *a[])
#endif
}
+ if (a[OVS_DP_ATTR_MASKS_CACHE_SIZE]) {
+ int err;
+ u32 cache_size;
+
+ cache_size = nla_get_u32(a[OVS_DP_ATTR_MASKS_CACHE_SIZE]);
+ err = ovs_flow_tbl_masks_cache_resize(&dp->table, cache_size);
+ if (err)
+ return err;
+ }
+
dp->user_features = user_features;
if (dp->user_features & OVS_DP_F_TC_RECIRC_SHARING)
@@ -1894,6 +1909,8 @@ static const struct nla_policy datapath_policy[OVS_DP_ATTR_MAX + 1] = {
[OVS_DP_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
[OVS_DP_ATTR_UPCALL_PID] = { .type = NLA_U32 },
[OVS_DP_ATTR_USER_FEATURES] = { .type = NLA_U32 },
+ [OVS_DP_ATTR_MASKS_CACHE_SIZE] = NLA_POLICY_RANGE(NLA_U32, 0,
+ PCPU_MIN_UNIT_SIZE / sizeof(struct mask_cache_entry)),
};
static const struct genl_ops dp_datapath_genl_ops[] = {
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index a5912ea05352..6527d84c3ea6 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -38,8 +38,8 @@
#define MASK_ARRAY_SIZE_MIN 16
#define REHASH_INTERVAL (10 * 60 * HZ)
+#define MC_DEFAULT_HASH_ENTRIES 256
#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;
@@ -341,15 +341,79 @@ static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
}
}
+static void __mask_cache_destroy(struct mask_cache *mc)
+{
+ free_percpu(mc->mask_cache);
+ kfree(mc);
+}
+
+static void mask_cache_rcu_cb(struct rcu_head *rcu)
+{
+ struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
+
+ __mask_cache_destroy(mc);
+}
+
+static struct mask_cache *tbl_mask_cache_alloc(u32 size)
+{
+ struct mask_cache_entry __percpu *cache = NULL;
+ struct mask_cache *new;
+
+ /* Only allow size to be 0, or a power of 2, and does not exceed
+ * percpu allocation size.
+ */
+ if ((!is_power_of_2(size) && size != 0) ||
+ (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
+ return NULL;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ new->cache_size = size;
+ if (new->cache_size > 0) {
+ cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
+ new->cache_size),
+ __alignof__(struct mask_cache_entry));
+ if (!cache) {
+ kfree(new);
+ return NULL;
+ }
+ }
+
+ new->mask_cache = cache;
+ return new;
+}
+int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
+{
+ struct mask_cache *mc = rcu_dereference(table->mask_cache);
+ struct mask_cache *new;
+
+ if (size == mc->cache_size)
+ return 0;
+
+ if ((!is_power_of_2(size) && size != 0) ||
+ (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
+ return -EINVAL;
+
+ new = tbl_mask_cache_alloc(size);
+ if (!new)
+ return -ENOMEM;
+
+ rcu_assign_pointer(table->mask_cache, new);
+ call_rcu(&mc->rcu, mask_cache_rcu_cb);
+
+ return 0;
+}
+
int ovs_flow_tbl_init(struct flow_table *table)
{
struct table_instance *ti, *ufid_ti;
+ struct mask_cache *mc;
struct mask_array *ma;
- table->mask_cache = __alloc_percpu(sizeof(struct mask_cache_entry) *
- MC_HASH_ENTRIES,
- __alignof__(struct mask_cache_entry));
- if (!table->mask_cache)
+ mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
+ if (!mc)
return -ENOMEM;
ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
@@ -367,6 +431,7 @@ int ovs_flow_tbl_init(struct flow_table *table)
rcu_assign_pointer(table->ti, ti);
rcu_assign_pointer(table->ufid_ti, ufid_ti);
rcu_assign_pointer(table->mask_array, ma);
+ rcu_assign_pointer(table->mask_cache, mc);
table->last_rehash = jiffies;
table->count = 0;
table->ufid_count = 0;
@@ -377,7 +442,7 @@ int ovs_flow_tbl_init(struct flow_table *table)
free_mask_array:
__mask_array_destroy(ma);
free_mask_cache:
- free_percpu(table->mask_cache);
+ __mask_cache_destroy(mc);
return -ENOMEM;
}
@@ -453,9 +518,11 @@ 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);
+ struct mask_cache *mc = rcu_dereference(table->mask_cache);
+ struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
- free_percpu(table->mask_cache);
- call_rcu(&table->mask_array->rcu, mask_array_rcu_cb);
+ call_rcu(&mc->rcu, mask_cache_rcu_cb);
+ call_rcu(&ma->rcu, mask_array_rcu_cb);
table_instance_destroy(table, ti, ufid_ti, false);
}
@@ -724,6 +791,7 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
u32 *n_mask_hit,
u32 *n_cache_hit)
{
+ struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
struct mask_array *ma = rcu_dereference(tbl->mask_array);
struct table_instance *ti = rcu_dereference(tbl->ti);
struct mask_cache_entry *entries, *ce;
@@ -733,7 +801,7 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
*n_mask_hit = 0;
*n_cache_hit = 0;
- if (unlikely(!skb_hash)) {
+ if (unlikely(!skb_hash || mc->cache_size == 0)) {
u32 mask_index = 0;
u32 cache = 0;
@@ -749,11 +817,11 @@ struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
ce = NULL;
hash = skb_hash;
- entries = this_cpu_ptr(tbl->mask_cache);
+ entries = this_cpu_ptr(mc->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);
+ int index = hash & (mc->cache_size - 1);
struct mask_cache_entry *e;
e = &entries[index];
@@ -867,6 +935,13 @@ int ovs_flow_tbl_num_masks(const struct flow_table *table)
return READ_ONCE(ma->count);
}
+u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
+{
+ struct mask_cache *mc = rcu_dereference(table->mask_cache);
+
+ return READ_ONCE(mc->cache_size);
+}
+
static struct table_instance *table_instance_expand(struct table_instance *ti,
bool ufid)
{
@@ -1095,8 +1170,8 @@ void ovs_flow_masks_rebalance(struct flow_table *table)
for (i = 0; i < masks_entries; i++) {
int index = masks_and_count[i].index;
- new->masks[new->count++] =
- rcu_dereference_ovsl(ma->masks[index]);
+ if (ovsl_dereference(ma->masks[index]))
+ new->masks[new->count++] = ma->masks[index];
}
rcu_assign_pointer(table->mask_array, new);
diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h
index 325e939371d8..74ce48fecba9 100644
--- a/net/openvswitch/flow_table.h
+++ b/net/openvswitch/flow_table.h
@@ -27,6 +27,12 @@ struct mask_cache_entry {
u32 mask_index;
};
+struct mask_cache {
+ struct rcu_head rcu;
+ u32 cache_size; /* Must be ^2 value. */
+ struct mask_cache_entry __percpu *mask_cache;
+};
+
struct mask_count {
int index;
u64 counter;
@@ -53,7 +59,7 @@ struct table_instance {
struct flow_table {
struct table_instance __rcu *ti;
struct table_instance __rcu *ufid_ti;
- struct mask_cache_entry __percpu *mask_cache;
+ struct mask_cache __rcu *mask_cache;
struct mask_array __rcu *mask_array;
unsigned long last_rehash;
unsigned int count;
@@ -77,6 +83,8 @@ int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
const struct sw_flow_mask *mask);
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow);
int ovs_flow_tbl_num_masks(const struct flow_table *table);
+u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table);
+int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size);
struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *table,
u32 *bucket, u32 *idx);
struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *,
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements
2020-07-31 12:20 [PATCH net-next v4 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
2020-07-31 12:20 ` [PATCH net-next v4 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
2020-07-31 12:21 ` [PATCH net-next v4 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
@ 2020-08-03 22:18 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2020-08-03 22:18 UTC (permalink / raw)
To: echaudro; +Cc: netdev, dev, kuba, pabeni, pshelar, fw, xiangxia.m.yue
From: Eelco Chaudron <echaudro@redhat.com>
Date: Fri, 31 Jul 2020 14:20:34 +0200
> This patchset adds two enhancements to the Open vSwitch masks cache.
>
> Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Series applied, thank you.
^ permalink raw reply [flat|nested] 4+ messages in thread