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| author | Alexei Starovoitov <ast@kernel.org> | 2022-09-03 00:10:51 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-09-05 16:33:06 +0300 |
| commit | 8d5a8011b35d387c490a5c977b1d9eb4798aa071 (patch) | |
| tree | 83f515cd987e8a9209f74a1941cc12df0fa0cb71 /kernel/bpf/syscall.c | |
| parent | 7c266178aa51dd2d4fda1312c5990a8a82c83d70 (diff) | |
| download | linux-8d5a8011b35d387c490a5c977b1d9eb4798aa071.tar.xz | |
bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
SLAB_TYPESAFE_BY_RCU makes kmem_caches non mergeable and slows down
kmem_cache_destroy. All bpf_mem_cache are safe to share across different maps
and programs. Convert SLAB_TYPESAFE_BY_RCU to batched call_rcu. This change
solves the memory consumption issue, avoids kmem_cache_destroy latency and
keeps bpf hash map performance the same.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220902211058.60789-10-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e9d4622aef7..074c901fbb4e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -638,7 +638,10 @@ static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock) bpf_map_free_id(map, do_idr_lock); btf_put(map->btf); INIT_WORK(&map->work, bpf_map_free_deferred); - schedule_work(&map->work); + /* Avoid spawning kworkers, since they all might contend + * for the same mutex like slab_mutex. + */ + queue_work(system_unbound_wq, &map->work); } } |