* [PATCH net-next v2 0/2] net: openvswitch: masks cache enhancements
@ 2020-07-23 12:58 Eelco Chaudron
2020-07-23 12:58 ` [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
2020-07-23 12:58 ` [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
0 siblings, 2 replies; 6+ messages in thread
From: Eelco Chaudron @ 2020-07-23 12:58 UTC (permalink / raw)
To: netdev; +Cc: davem, dev, kuba, pabeni, pshelar, fw
This patchset adds two enhancements to the Open vSwitch masks cache.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Changes in v2:
- Fix sparse warnings
- Fix netlink policy items reported by Florian Westphal
Eelco Chaudron (2):
net: openvswitch: add masks cache hit counter
net: openvswitch: make masks cache size configurable
include/uapi/linux/openvswitch.h | 3 +
net/openvswitch/datapath.c | 19 ++++++-
net/openvswitch/datapath.h | 3 +
net/openvswitch/flow_table.c | 109 +++++++++++++++++++++++++++++++++-----
net/openvswitch/flow_table.h | 13 ++++-
5 files changed, 128 insertions(+), 19 deletions(-)
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter
2020-07-23 12:58 [PATCH net-next v2 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
@ 2020-07-23 12:58 ` Eelco Chaudron
2020-07-24 2:37 ` [ovs-dev] " Tonghao Zhang
2020-07-23 12:58 ` [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
1 sibling, 1 reply; 6+ messages in thread
From: Eelco Chaudron @ 2020-07-23 12:58 UTC (permalink / raw)
To: netdev; +Cc: davem, dev, kuba, pabeni, pshelar, fw
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>
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] 6+ messages in thread
* [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable
2020-07-23 12:58 [PATCH net-next v2 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
2020-07-23 12:58 ` [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
@ 2020-07-23 12:58 ` Eelco Chaudron
2020-07-23 16:42 ` Jakub Kicinski
1 sibling, 1 reply; 6+ messages in thread
From: Eelco Chaudron @ 2020-07-23 12:58 UTC (permalink / raw)
To: netdev; +Cc: davem, dev, kuba, pabeni, pshelar, fw
This patch makes the masks cache size configurable, or with
a size of 0, disable it.
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
include/uapi/linux/openvswitch.h | 1
net/openvswitch/datapath.c | 14 ++++++
net/openvswitch/flow_table.c | 90 ++++++++++++++++++++++++++++++++++----
net/openvswitch/flow_table.h | 10 ++++
4 files changed, 104 insertions(+), 11 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..114b2ddb8037 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 +1604,13 @@ static int ovs_dp_change(struct datapath *dp, struct nlattr *a[])
#endif
}
+ if (a[OVS_DP_ATTR_MASKS_CACHE_SIZE]) {
+ u32 cache_size;
+
+ cache_size = nla_get_u32(a[OVS_DP_ATTR_MASKS_CACHE_SIZE]);
+ ovs_flow_tbl_masks_cache_resize(&dp->table, cache_size);
+ }
+
dp->user_features = user_features;
if (dp->user_features & OVS_DP_F_TC_RECIRC_SHARING)
@@ -1894,6 +1906,8 @@ 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..386b7e7a0454 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 +341,76 @@ static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
}
}
+static void __mask_cache_destroy(struct mask_cache *mc)
+{
+ if (mc->mask_cache)
+ 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 ((size & (size - 1)) != 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(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;
+}
+
+void 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 || (size & (size - 1)) != 0)
+ return;
+
+ new = tbl_mask_cache_alloc(size);
+ if (!new)
+ return;
+
+ rcu_assign_pointer(table->mask_cache, new);
+ call_rcu(&mc->rcu, mask_cache_rcu_cb);
+}
+
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 +428,7 @@ 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 +439,7 @@ 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;
}
@@ -454,7 +516,7 @@ 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);
- free_percpu(table->mask_cache);
+ call_rcu(&table->mask_cache->rcu, mask_cache_rcu_cb);
call_rcu(&table->mask_array->rcu, mask_array_rcu_cb);
table_instance_destroy(table, ti, ufid_ti, false);
}
@@ -724,6 +786,7 @@ 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 +796,7 @@ 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 +812,11 @@ 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 +930,13 @@ 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)
{
diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h
index 325e939371d8..f2dba952db2f 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);
+void 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] 6+ messages in thread
* Re: [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable
2020-07-23 12:58 ` [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
@ 2020-07-23 16:42 ` Jakub Kicinski
2020-07-24 8:00 ` Eelco Chaudron
0 siblings, 1 reply; 6+ messages in thread
From: Jakub Kicinski @ 2020-07-23 16:42 UTC (permalink / raw)
To: Eelco Chaudron; +Cc: netdev, davem, dev, pabeni, pshelar, fw
On Thu, 23 Jul 2020 14:58:31 +0200 Eelco Chaudron wrote:
> + if ((size & (size - 1)) != 0 ||
is_power_of_2() ?
> + (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
> + return NULL;
> + new->cache_size = size;
> + if (new->cache_size > 0) {
> + cache = __alloc_percpu(sizeof(struct mask_cache_entry) *
> + new->cache_size,
array_size() ?
> + __alignof__(struct mask_cache_entry));
> +
No need for the new line here
> + if (!cache) {
> + kfree(new);
> + return NULL;
> + }
> + }
> + if (size == mc->cache_size || (size & (size - 1)) != 0)
why check "is power of 2" twice?
> @@ -454,7 +516,7 @@ 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);
>
> - free_percpu(table->mask_cache);
> + call_rcu(&table->mask_cache->rcu, mask_cache_rcu_cb);
> call_rcu(&table->mask_array->rcu, mask_array_rcu_cb);
> table_instance_destroy(table, ti, ufid_ti, false);
> }
This adds a new warning :(
net/openvswitch/flow_table.c:519:24: warning: incorrect type in argument 1 (different address spaces)
net/openvswitch/flow_table.c:519:24: expected struct callback_head *head
net/openvswitch/flow_table.c:519:24: got struct callback_head [noderef] __rcu *
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [ovs-dev] [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter
2020-07-23 12:58 ` [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
@ 2020-07-24 2:37 ` Tonghao Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Tonghao Zhang @ 2020-07-24 2:37 UTC (permalink / raw)
To: Eelco Chaudron
Cc: Linux Kernel Network Developers, ovs dev, Florian Westphal,
Jakub Kicinski, Paolo Abeni, David Miller
On Thu, Jul 23, 2020 at 8:58 PM Eelco Chaudron <echaudro@redhat.com> wrote:
>
> 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>
> Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
LGTM
Reviewed-by: Tonghao Zhang <xiangxia.m.yue@gmail.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,
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
--
Best regards, Tonghao
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable
2020-07-23 16:42 ` Jakub Kicinski
@ 2020-07-24 8:00 ` Eelco Chaudron
0 siblings, 0 replies; 6+ messages in thread
From: Eelco Chaudron @ 2020-07-24 8:00 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: netdev, davem, dev, pabeni, pshelar, fw
On 23 Jul 2020, at 18:42, Jakub Kicinski wrote:
> On Thu, 23 Jul 2020 14:58:31 +0200 Eelco Chaudron wrote:
>> + if ((size & (size - 1)) != 0 ||
>
> is_power_of_2() ?
Was not aware of this macro, will replace…
>
>> + (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
>> + return NULL;
>
>> + new->cache_size = size;
>> + if (new->cache_size > 0) {
>> + cache = __alloc_percpu(sizeof(struct mask_cache_entry) *
>> + new->cache_size,
>
> array_size() ?
Will change to:
cache = __alloc_percpu(array_size(
sizeof(struct mask_cache_entry),
new->cache_size),
__alignof__(struct mask_cache_entry));
if (!cache) {
>
>> + __alignof__(struct mask_cache_entry));
>> +
>
> No need for the new line here
Will remove
>> + if (!cache) {
>> + kfree(new);
>> + return NULL;
>> + }
>> + }
>
>> + if (size == mc->cache_size || (size & (size - 1)) != 0)
>
> why check "is power of 2" twice?
Will remove as it will always call tbl_mask_cache_alloc() which has the
check above.
>
>> @@ -454,7 +516,7 @@ 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);
>>
>> - free_percpu(table->mask_cache);
>> + call_rcu(&table->mask_cache->rcu, mask_cache_rcu_cb);
>> call_rcu(&table->mask_array->rcu, mask_array_rcu_cb);
>> table_instance_destroy(table, ti, ufid_ti, false);
>> }
>
> This adds a new warning :(
>
> net/openvswitch/flow_table.c:519:24: warning: incorrect type in
> argument 1 (different address spaces)
> net/openvswitch/flow_table.c:519:24: expected struct callback_head
> *head
> net/openvswitch/flow_table.c:519:24: got struct callback_head
> [noderef] __rcu *
:( Yes my diff with older did not work… Sure I’ve fixed them all now
:)
Will sent out a V3 after some testing…
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-07-24 8:00 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-23 12:58 [PATCH net-next v2 0/2] net: openvswitch: masks cache enhancements Eelco Chaudron
2020-07-23 12:58 ` [PATCH net-next v2 1/2] net: openvswitch: add masks cache hit counter Eelco Chaudron
2020-07-24 2:37 ` [ovs-dev] " Tonghao Zhang
2020-07-23 12:58 ` [PATCH net-next v2 2/2] net: openvswitch: make masks cache size configurable Eelco Chaudron
2020-07-23 16:42 ` Jakub Kicinski
2020-07-24 8:00 ` Eelco Chaudron
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