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bpf: introduce per-cpu cgroup local storage

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This commit introduced per-cpu cgroup local storage.

Per-cpu cgroup local storage is very similar to simple cgroup storage
(let's call it shared), except all the data is per-cpu.

The main goal of per-cpu variant is to implement super fast
counters (e.g. packet counters), which don't require neither
lookups, neither atomic operations.

>From userspace's point of view, accessing a per-cpu cgroup storage
is similar to other per-cpu map types (e.g. per-cpu hashmaps and
arrays).

Writing to a per-cpu cgroup storage is not atomic, but is performed
by copying longs, so some minimal atomicity is here, exactly
as with other per-cpu maps.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Roman Gushchin
2018-09-28 14:45:43 +00:00
committed by Daniel Borkmann
parent f294b37ec7
commit b741f16303
8 changed files with 179 additions and 28 deletions
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20
include/linux/bpf-cgroup.h
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@@ -37,7 +37,10 @@ struct bpf_storage_buffer {
};
struct bpf_cgroup_storage {
struct bpf_storage_buffer *buf;
union {
struct bpf_storage_buffer *buf;
void __percpu *percpu_buf;
};
struct bpf_cgroup_storage_map *map;
struct bpf_cgroup_storage_key key;
struct list_head list;
@@ -109,6 +112,9 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
static inline enum bpf_cgroup_storage_type cgroup_storage_type(
struct bpf_map *map)
{
if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
return BPF_CGROUP_STORAGE_PERCPU;
return BPF_CGROUP_STORAGE_SHARED;
}
@@ -131,6 +137,10 @@ void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage);
int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *map);
void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *map);
int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
void *value, u64 flags);
/* Wrappers for __cgroup_bpf_run_filter_skb() guarded by cgroup_bpf_enabled. */
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \
({ \
@@ -285,6 +295,14 @@ static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(
struct bpf_prog *prog, enum bpf_cgroup_storage_type stype) { return 0; }
static inline void bpf_cgroup_storage_free(
struct bpf_cgroup_storage *storage) {}
static inline int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key,
void *value) {
return 0;
}
static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map,
void *key, void *value, u64 flags) {
return 0;
}
#define cgroup_bpf_enabled (0)
#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0)