bpf: Eliminate rlimit-based memory accounting for bpf ringbuffer

Do not use rlimit-based memory accounting for bpf ringbuffer.
It has been replaced with the memcg-based memory accounting.

bpf_ringbuf_alloc() can't return anything except ERR_PTR(-ENOMEM)
and a valid pointer, so to simplify the code make it return NULL
in the first case. This allows to drop a couple of lines in
ringbuf_map_alloc() and also makes it look similar to other memory
allocating function like kmalloc().

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-28-guro@fb.com
This commit is contained in:
Roman Gushchin 2020-12-01 13:58:53 -08:00 committed by Alexei Starovoitov
parent db54330d3e
commit abbdd0813f

View File

@ -48,7 +48,6 @@ struct bpf_ringbuf {
struct bpf_ringbuf_map {
struct bpf_map map;
struct bpf_map_memory memory;
struct bpf_ringbuf *rb;
};
@ -131,7 +130,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
rb = bpf_ringbuf_area_alloc(data_sz, numa_node);
if (!rb)
return ERR_PTR(-ENOMEM);
return NULL;
spin_lock_init(&rb->spinlock);
init_waitqueue_head(&rb->waitq);
@ -147,8 +146,6 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
{
struct bpf_ringbuf_map *rb_map;
u64 cost;
int err;
if (attr->map_flags & ~RINGBUF_CREATE_FLAG_MASK)
return ERR_PTR(-EINVAL);
@ -170,26 +167,13 @@ static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
bpf_map_init_from_attr(&rb_map->map, attr);
cost = sizeof(struct bpf_ringbuf_map) +
sizeof(struct bpf_ringbuf) +
attr->max_entries;
err = bpf_map_charge_init(&rb_map->map.memory, cost);
if (err)
goto err_free_map;
rb_map->rb = bpf_ringbuf_alloc(attr->max_entries, rb_map->map.numa_node);
if (IS_ERR(rb_map->rb)) {
err = PTR_ERR(rb_map->rb);
goto err_uncharge;
if (!rb_map->rb) {
kfree(rb_map);
return ERR_PTR(-ENOMEM);
}
return &rb_map->map;
err_uncharge:
bpf_map_charge_finish(&rb_map->map.memory);
err_free_map:
kfree(rb_map);
return ERR_PTR(err);
}
static void bpf_ringbuf_free(struct bpf_ringbuf *rb)