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bpf: populate the per-cpu insertions/deletions counters for hashmaps

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Initialize and utilize the per-cpu insertions/deletions counters for hash-based
maps. Non-trivial changes only apply to the preallocated maps for which the
{inc,dec}_elem_count functions are not called, as there's no need in counting
elements to sustain proper map operations.

To increase/decrease percpu counters for preallocated maps we add raw calls to
the bpf_map_{inc,dec}_elem_count functions so that the impact is minimal. For
dynamically allocated maps we add corresponding calls to the existing
{inc,dec}_elem_count functions.

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230706133932.45883-4-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Anton Protopopov 2023-07-06 13:39:30 +00:00 committed by Alexei Starovoitov
parent 803370d3d3
commit 9bc421b6be
1 changed files with 20 additions and 2 deletions
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22
kernel/bpf/hashtab.c
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@ -302,6 +302,7 @@ static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
struct htab_elem *l;
if (node) {
bpf_map_inc_elem_count(&htab->map);
l = container_of(node, struct htab_elem, lru_node);
memcpy(l->key, key, htab->map.key_size);
return l;
@ -510,12 +511,16 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
htab->n_buckets > U32_MAX / sizeof(struct bucket))
goto free_htab;
err = bpf_map_init_elem_count(&htab->map);
if (err)
goto free_htab;
err = -ENOMEM;
htab->buckets = bpf_map_area_alloc(htab->n_buckets *
sizeof(struct bucket),
htab->map.numa_node);
if (!htab->buckets)
goto free_htab;
goto free_elem_count;
for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) {
htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map,
@ -593,6 +598,8 @@ free_map_locked:
bpf_map_area_free(htab->buckets);
bpf_mem_alloc_destroy(&htab->pcpu_ma);
bpf_mem_alloc_destroy(&htab->ma);
free_elem_count:
bpf_map_free_elem_count(&htab->map);
free_htab:
lockdep_unregister_key(&htab->lockdep_key);
bpf_map_area_free(htab);
@ -804,6 +811,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
if (l == tgt_l) {
hlist_nulls_del_rcu(&l->hash_node);
check_and_free_fields(htab, l);
bpf_map_dec_elem_count(&htab->map);
break;
}
@ -900,6 +908,8 @@ static bool is_map_full(struct bpf_htab *htab)
static void inc_elem_count(struct bpf_htab *htab)
{
bpf_map_inc_elem_count(&htab->map);
if (htab->use_percpu_counter)
percpu_counter_add_batch(&htab->pcount, 1, PERCPU_COUNTER_BATCH);
else
@ -908,6 +918,8 @@ static void inc_elem_count(struct bpf_htab *htab)
static void dec_elem_count(struct bpf_htab *htab)
{
bpf_map_dec_elem_count(&htab->map);
if (htab->use_percpu_counter)
percpu_counter_add_batch(&htab->pcount, -1, PERCPU_COUNTER_BATCH);
else
@ -920,6 +932,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
htab_put_fd_value(htab, l);
if (htab_is_prealloc(htab)) {
bpf_map_dec_elem_count(&htab->map);
check_and_free_fields(htab, l);
__pcpu_freelist_push(&htab->freelist, &l->fnode);
} else {
@ -1000,6 +1013,7 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
if (!l)
return ERR_PTR(-E2BIG);
l_new = container_of(l, struct htab_elem, fnode);
bpf_map_inc_elem_count(&htab->map);
}
} else {
if (is_map_full(htab))
@ -1168,6 +1182,7 @@ err:
static void htab_lru_push_free(struct bpf_htab *htab, struct htab_elem *elem)
{
check_and_free_fields(htab, elem);
bpf_map_dec_elem_count(&htab->map);
bpf_lru_push_free(&htab->lru, &elem->lru_node);
}
@ -1357,8 +1372,10 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
err:
htab_unlock_bucket(htab, b, hash, flags);
err_lock_bucket:
if (l_new)
if (l_new) {
bpf_map_dec_elem_count(&htab->map);
bpf_lru_push_free(&htab->lru, &l_new->lru_node);
}
return ret;
}
@ -1523,6 +1540,7 @@ static void htab_map_free(struct bpf_map *map)
prealloc_destroy(htab);
}
bpf_map_free_elem_count(map);
free_percpu(htab->extra_elems);
bpf_map_area_free(htab->buckets);
bpf_mem_alloc_destroy(&htab->pcpu_ma);