bpf: Add BPF_MAP_TYPE_LRU_PERCPU_HASH
Provide a LRU version of the existing BPF_MAP_TYPE_PERCPU_HASH Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin KaFai Lau
David S. Miller
Родитель
29ba732acb
Коммит
8f8449384e
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@ -86,6 +86,7 @@ enum bpf_map_type {
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BPF_MAP_TYPE_STACK_TRACE,
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BPF_MAP_TYPE_CGROUP_ARRAY,
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BPF_MAP_TYPE_LRU_HASH,
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BPF_MAP_TYPE_LRU_PERCPU_HASH,
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};
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enum bpf_prog_type {
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@ -108,7 +109,7 @@ enum bpf_prog_type {
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#define BPF_F_NO_PREALLOC (1U << 0)
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/* Instead of having one common LRU list in the
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* BPF_MAP_TYPE_LRU_HASH map, use a percpu LRU list
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* BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
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* which can scale and perform better.
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* Note, the LRU nodes (including free nodes) cannot be moved
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* across different LRU lists.
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@ -62,7 +62,14 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
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static bool htab_is_lru(const struct bpf_htab *htab)
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{
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return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH;
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return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
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htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
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}
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static bool htab_is_percpu(const struct bpf_htab *htab)
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{
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return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
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}
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static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
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@ -85,7 +92,7 @@ static void htab_free_elems(struct bpf_htab *htab)
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{
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int i;
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if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
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if (!htab_is_percpu(htab))
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goto free_elems;
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for (i = 0; i < htab->map.max_entries; i++) {
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@ -122,7 +129,7 @@ static int prealloc_init(struct bpf_htab *htab)
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if (!htab->elems)
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return -ENOMEM;
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if (htab->map.map_type != BPF_MAP_TYPE_PERCPU_HASH)
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if (!htab_is_percpu(htab))
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goto skip_percpu_elems;
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for (i = 0; i < htab->map.max_entries; i++) {
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@ -195,8 +202,10 @@ static int alloc_extra_elems(struct bpf_htab *htab)
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/* Called from syscall */
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static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
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{
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bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_HASH;
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bool lru = attr->map_type == BPF_MAP_TYPE_LRU_HASH;
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bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
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bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
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attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
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/* percpu_lru means each cpu has its own LRU list.
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* it is different from BPF_MAP_TYPE_PERCPU_HASH where
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* the map's value itself is percpu. percpu_lru has
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@ -823,12 +832,84 @@ err:
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return ret;
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}
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static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
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void *value, u64 map_flags,
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bool onallcpus)
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{
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struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
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struct htab_elem *l_new = NULL, *l_old;
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struct hlist_head *head;
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unsigned long flags;
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struct bucket *b;
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u32 key_size, hash;
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int ret;
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if (unlikely(map_flags > BPF_EXIST))
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/* unknown flags */
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return -EINVAL;
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WARN_ON_ONCE(!rcu_read_lock_held());
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key_size = map->key_size;
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hash = htab_map_hash(key, key_size);
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b = __select_bucket(htab, hash);
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head = &b->head;
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/* For LRU, we need to alloc before taking bucket's
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* spinlock because LRU's elem alloc may need
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* to remove older elem from htab and this removal
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* operation will need a bucket lock.
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*/
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if (map_flags != BPF_EXIST) {
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l_new = prealloc_lru_pop(htab, key, hash);
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if (!l_new)
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return -ENOMEM;
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}
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/* bpf_map_update_elem() can be called in_irq() */
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raw_spin_lock_irqsave(&b->lock, flags);
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l_old = lookup_elem_raw(head, hash, key, key_size);
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ret = check_flags(htab, l_old, map_flags);
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if (ret)
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goto err;
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if (l_old) {
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bpf_lru_node_set_ref(&l_old->lru_node);
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/* per-cpu hash map can update value in-place */
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pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
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value, onallcpus);
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} else {
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pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
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value, onallcpus);
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hlist_add_head_rcu(&l_new->hash_node, head);
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l_new = NULL;
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}
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ret = 0;
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err:
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raw_spin_unlock_irqrestore(&b->lock, flags);
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if (l_new)
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bpf_lru_push_free(&htab->lru, &l_new->lru_node);
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return ret;
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}
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static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
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void *value, u64 map_flags)
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{
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return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
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}
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static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
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void *value, u64 map_flags)
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{
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return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
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false);
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}
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/* Called from syscall or from eBPF program */
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static int htab_map_delete_elem(struct bpf_map *map, void *key)
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{
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@ -976,8 +1057,21 @@ static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
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return NULL;
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}
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static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
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{
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struct htab_elem *l = __htab_map_lookup_elem(map, key);
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if (l) {
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bpf_lru_node_set_ref(&l->lru_node);
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return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
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}
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return NULL;
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}
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int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
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{
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struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
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struct htab_elem *l;
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void __percpu *pptr;
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int ret = -ENOENT;
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@ -993,6 +1087,8 @@ int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
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l = __htab_map_lookup_elem(map, key);
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if (!l)
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goto out;
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if (htab_is_lru(htab))
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bpf_lru_node_set_ref(&l->lru_node);
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pptr = htab_elem_get_ptr(l, map->key_size);
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for_each_possible_cpu(cpu) {
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bpf_long_memcpy(value + off,
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@ -1008,10 +1104,16 @@ out:
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int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
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u64 map_flags)
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{
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struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
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int ret;
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rcu_read_lock();
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ret = __htab_percpu_map_update_elem(map, key, value, map_flags, true);
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if (htab_is_lru(htab))
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ret = __htab_lru_percpu_map_update_elem(map, key, value,
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map_flags, true);
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else
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ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
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true);
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rcu_read_unlock();
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return ret;
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@ -1031,11 +1133,26 @@ static struct bpf_map_type_list htab_percpu_type __read_mostly = {
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.type = BPF_MAP_TYPE_PERCPU_HASH,
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};
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static const struct bpf_map_ops htab_lru_percpu_ops = {
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.map_alloc = htab_map_alloc,
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.map_free = htab_map_free,
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.map_get_next_key = htab_map_get_next_key,
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.map_lookup_elem = htab_lru_percpu_map_lookup_elem,
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.map_update_elem = htab_lru_percpu_map_update_elem,
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.map_delete_elem = htab_lru_map_delete_elem,
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};
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static struct bpf_map_type_list htab_lru_percpu_type __read_mostly = {
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.ops = &htab_lru_percpu_ops,
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.type = BPF_MAP_TYPE_LRU_PERCPU_HASH,
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};
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static int __init register_htab_map(void)
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{
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bpf_register_map_type(&htab_type);
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bpf_register_map_type(&htab_percpu_type);
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bpf_register_map_type(&htab_lru_type);
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bpf_register_map_type(&htab_lru_percpu_type);
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return 0;
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}
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late_initcall(register_htab_map);
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@ -292,6 +292,7 @@ static int map_lookup_elem(union bpf_attr *attr)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
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value_size = round_up(map->value_size, 8) * num_possible_cpus();
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else
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@ -302,7 +303,8 @@ static int map_lookup_elem(union bpf_attr *attr)
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if (!value)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
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err = bpf_percpu_hash_copy(map, key, value);
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} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
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err = bpf_percpu_array_copy(map, key, value);
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@ -366,6 +368,7 @@ static int map_update_elem(union bpf_attr *attr)
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goto free_key;
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
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value_size = round_up(map->value_size, 8) * num_possible_cpus();
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else
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@ -385,7 +388,8 @@ static int map_update_elem(union bpf_attr *attr)
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*/
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preempt_disable();
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__this_cpu_inc(bpf_prog_active);
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
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err = bpf_percpu_hash_update(map, key, value, attr->flags);
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} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
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err = bpf_percpu_array_update(map, key, value, attr->flags);
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