From 9bf24f594c6acf676fb8c229f152c21bfb915ddb Mon Sep 17 00:00:00 2001 From: Eelco Chaudron Date: Fri, 31 Jul 2020 14:21:34 +0200 Subject: net: openvswitch: make masks cache size configurable This patch makes the masks cache size configurable, or with a size of 0, disable it. Reviewed-by: Paolo Abeni Reviewed-by: Tonghao Zhang Signed-off-by: Eelco Chaudron Signed-off-by: David S. Miller --- 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 f45fee760504..42f8cc70bb2c 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) @@ -1887,6 +1902,8 @@ 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 @@ free_ti: 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 *, -- cgit v1.2.3