diff options
| author | Hou Tao <houtao1@huawei.com> | 2025-04-01 14:22:49 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-04-09 20:12:54 -0700 |
| commit | 6704b1e8cfc5eed264065735fe00a1dd8a0bffef (patch) | |
| tree | 3dfc0e96e3a895ac80bef6bb9d375b2532022933 | |
| parent | e8a65856c75d518d0bb15f38c90a4fd264ba1d3a (diff) | |
bpf: Don't allocate per-cpu extra_elems for fd htab
The update of element in fd htab is in-place now, therefore, there is no
need to allocate per-cpu extra_elems, just remove it.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250401062250.543403-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/hashtab.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 097992efef05..2e18d7e50d9b 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -206,9 +206,13 @@ static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) return (struct htab_elem *) (htab->elems + i * (u64)htab->elem_size); } +/* Both percpu and fd htab support in-place update, so no need for + * extra elem. LRU itself can remove the least used element, so + * there is no need for an extra elem during map_update. + */ static bool htab_has_extra_elems(struct bpf_htab *htab) { - return !htab_is_percpu(htab) && !htab_is_lru(htab); + return !htab_is_percpu(htab) && !htab_is_lru(htab) && !is_fd_htab(htab); } static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab) @@ -464,8 +468,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) { bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH || attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); - bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH || - attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); /* percpu_lru means each cpu has its own LRU list. * it is different from BPF_MAP_TYPE_PERCPU_HASH where * the map's value itself is percpu. percpu_lru has @@ -560,10 +562,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) if (err) goto free_map_locked; - if (!percpu && !lru) { - /* lru itself can remove the least used element, so - * there is no need for an extra elem during map_update. - */ + if (htab_has_extra_elems(htab)) { err = alloc_extra_elems(htab); if (err) goto free_prealloc; |