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author | 2020-01-15 14:00:36 -0800 | |
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committer | 2020-01-15 14:07:47 -0800 | |
commit | 990bca1fc8ad48f7f8b0786b739a9408017b7a74 (patch) | |
tree | 961ad3ec3d792a2ea195989729709438de87d127 /tools | |
parent | selftests/bpf: Add a test for attaching a bpf fentry/fexit trace to an XDP program (diff) | |
parent | selftests/bpf: Add batch ops testing to array bpf map (diff) | |
download | wireguard-linux-990bca1fc8ad48f7f8b0786b739a9408017b7a74.tar.xz wireguard-linux-990bca1fc8ad48f7f8b0786b739a9408017b7a74.zip |
Merge branch 'bpf-batch-ops'
Brian Vazquez says:
====================
This patch series introduce batch ops that can be added to bpf maps to
lookup/lookup_and_delete/update/delete more than 1 element at the time,
this is specially useful when syscall overhead is a problem and in case
of hmap it will provide a reliable way of traversing them.
The implementation inclues a generic approach that could potentially be
used by any bpf map and adds it to arraymap, it also includes the specific
implementation of hashmaps which are traversed using buckets instead
of keys.
The bpf syscall subcommands introduced are:
BPF_MAP_LOOKUP_BATCH
BPF_MAP_LOOKUP_AND_DELETE_BATCH
BPF_MAP_UPDATE_BATCH
BPF_MAP_DELETE_BATCH
The UAPI attribute is:
struct { /* struct used by BPF_MAP_*_BATCH commands */
__aligned_u64 in_batch; /* start batch,
* NULL to start from beginning
*/
__aligned_u64 out_batch; /* output: next start batch */
__aligned_u64 keys;
__aligned_u64 values;
__u32 count; /* input/output:
* input: # of key/value
* elements
* output: # of filled elements
*/
__u32 map_fd;
__u64 elem_flags;
__u64 flags;
} batch;
in_batch and out_batch are only used for lookup and lookup_and_delete since
those are the only two operations that attempt to traverse the map.
update/delete batch ops should provide the keys/values that user wants
to modify.
Here are the previous discussions on the batch processing:
- https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/
- https://lore.kernel.org/bpf/20190829064502.2750303-1-yhs@fb.com/
- https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/
Changelog sinve v4:
- Remove unnecessary checks from libbpf API (Andrii Nakryiko)
- Move DECLARE_LIBBPF_OPTS with all var declarations (Andrii Nakryiko)
- Change bucket internal buffer size to 5 entries (Yonghong Song)
- Fix some minor bugs in hashtab batch ops implementation (Yonghong Song)
Changelog sinve v3:
- Do not use copy_to_user inside atomic region (Yonghong Song)
- Use _opts approach on libbpf APIs (Andrii Nakryiko)
- Drop generic_map_lookup_and_delete_batch support
- Free malloc-ed memory in tests (Yonghong Song)
- Reverse christmas tree (Yonghong Song)
- Add acked labels
Changelog sinve v2:
- Add generic batch support for lpm_trie and test it (Yonghong Song)
- Use define MAP_LOOKUP_RETRIES for retries (John Fastabend)
- Return errors directly and remove labels (Yonghong Song)
- Insert new API functions into libbpf alphabetically (Yonghong Song)
- Change hlist_nulls_for_each_entry_rcu to
hlist_nulls_for_each_entry_safe in htab batch ops (Yonghong Song)
Changelog since v1:
- Fix SOB ordering and remove Co-authored-by tag (Alexei Starovoitov)
Changelog since RFC:
- Change batch to in_batch and out_batch to support more flexible opaque
values to iterate the bpf maps.
- Remove update/delete specific batch ops for htab and use the generic
implementations instead.
====================
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to '')
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 21 | ||||
-rw-r--r-- | tools/lib/bpf/bpf.c | 58 | ||||
-rw-r--r-- | tools/lib/bpf/bpf.h | 22 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.map | 4 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/map_tests/array_map_batch_ops.c | 129 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c | 283 |
6 files changed, 517 insertions, 0 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index a88837d4dd18..033d90a2282d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -107,6 +107,10 @@ enum bpf_cmd { BPF_MAP_LOOKUP_AND_DELETE_ELEM, BPF_MAP_FREEZE, BPF_BTF_GET_NEXT_ID, + BPF_MAP_LOOKUP_BATCH, + BPF_MAP_LOOKUP_AND_DELETE_BATCH, + BPF_MAP_UPDATE_BATCH, + BPF_MAP_DELETE_BATCH, }; enum bpf_map_type { @@ -420,6 +424,23 @@ union bpf_attr { __u64 flags; }; + struct { /* struct used by BPF_MAP_*_BATCH commands */ + __aligned_u64 in_batch; /* start batch, + * NULL to start from beginning + */ + __aligned_u64 out_batch; /* output: next start batch */ + __aligned_u64 keys; + __aligned_u64 values; + __u32 count; /* input/output: + * input: # of key/value + * elements + * output: # of filled elements + */ + __u32 map_fd; + __u64 elem_flags; + __u64 flags; + } batch; + struct { /* anonymous struct used by BPF_PROG_LOAD command */ __u32 prog_type; /* one of enum bpf_prog_type */ __u32 insn_cnt; diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 500afe478e94..317727d61214 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -452,6 +452,64 @@ int bpf_map_freeze(int fd) return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr)); } +static int bpf_map_batch_common(int cmd, int fd, void *in_batch, + void *out_batch, void *keys, void *values, + __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + union bpf_attr attr = {}; + int ret; + + if (!OPTS_VALID(opts, bpf_map_batch_opts)) + return -EINVAL; + + memset(&attr, 0, sizeof(attr)); + attr.batch.map_fd = fd; + attr.batch.in_batch = ptr_to_u64(in_batch); + attr.batch.out_batch = ptr_to_u64(out_batch); + attr.batch.keys = ptr_to_u64(keys); + attr.batch.values = ptr_to_u64(values); + attr.batch.count = *count; + attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0); + attr.batch.flags = OPTS_GET(opts, flags, 0); + + ret = sys_bpf(cmd, &attr, sizeof(attr)); + *count = attr.batch.count; + + return ret; +} + +int bpf_map_delete_batch(int fd, void *keys, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL, + NULL, keys, NULL, count, opts); +} + +int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys, + void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch, + out_batch, keys, values, count, opts); +} + +int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch, + void *keys, void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH, + fd, in_batch, out_batch, keys, values, + count, opts); +} + +int bpf_map_update_batch(int fd, void *keys, void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL, + keys, values, count, opts); +} + int bpf_obj_pin(int fd, const char *pathname) { union bpf_attr attr; diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 56341d117e5b..b976e77316cc 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -127,6 +127,28 @@ LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key, LIBBPF_API int bpf_map_delete_elem(int fd, const void *key); LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key); LIBBPF_API int bpf_map_freeze(int fd); + +struct bpf_map_batch_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + __u64 elem_flags; + __u64 flags; +}; +#define bpf_map_batch_opts__last_field flags + +LIBBPF_API int bpf_map_delete_batch(int fd, void *keys, + __u32 *count, + const struct bpf_map_batch_opts *opts); +LIBBPF_API int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, + void *keys, void *values, __u32 *count, + const struct bpf_map_batch_opts *opts); +LIBBPF_API int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, + void *out_batch, void *keys, + void *values, __u32 *count, + const struct bpf_map_batch_opts *opts); +LIBBPF_API int bpf_map_update_batch(int fd, void *keys, void *values, + __u32 *count, + const struct bpf_map_batch_opts *opts); + LIBBPF_API int bpf_obj_pin(int fd, const char *pathname); LIBBPF_API int bpf_obj_get(const char *pathname); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index a19f04e6e3d9..1902a0fc6afc 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -214,6 +214,10 @@ LIBBPF_0.0.7 { btf_dump__emit_type_decl; bpf_link__disconnect; bpf_map__attach_struct_ops; + bpf_map_delete_batch; + bpf_map_lookup_and_delete_batch; + bpf_map_lookup_batch; + bpf_map_update_batch; bpf_object__find_program_by_name; bpf_object__attach_skeleton; bpf_object__destroy_skeleton; diff --git a/tools/testing/selftests/bpf/map_tests/array_map_batch_ops.c b/tools/testing/selftests/bpf/map_tests/array_map_batch_ops.c new file mode 100644 index 000000000000..f0a64d8ac59a --- /dev/null +++ b/tools/testing/selftests/bpf/map_tests/array_map_batch_ops.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <stdio.h> +#include <errno.h> +#include <string.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +#include <test_maps.h> + +static void map_batch_update(int map_fd, __u32 max_entries, int *keys, + int *values) +{ + int i, err; + DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts, + .elem_flags = 0, + .flags = 0, + ); + + for (i = 0; i < max_entries; i++) { + keys[i] = i; + values[i] = i + 1; + } + + err = bpf_map_update_batch(map_fd, keys, values, &max_entries, &opts); + CHECK(err, "bpf_map_update_batch()", "error:%s\n", strerror(errno)); +} + +static void map_batch_verify(int *visited, __u32 max_entries, + int *keys, int *values) +{ + int i; + + memset(visited, 0, max_entries * sizeof(*visited)); + for (i = 0; i < max_entries; i++) { + CHECK(keys[i] + 1 != values[i], "key/value checking", + "error: i %d key %d value %d\n", i, keys[i], values[i]); + visited[i] = 1; + } + for (i = 0; i < max_entries; i++) { + CHECK(visited[i] != 1, "visited checking", + "error: keys array at index %d missing\n", i); + } +} + +void test_array_map_batch_ops(void) +{ + struct bpf_create_map_attr xattr = { + .name = "array_map", + .map_type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + }; + int map_fd, *keys, *values, *visited; + __u32 count, total, total_success; + const __u32 max_entries = 10; + bool nospace_err; + __u64 batch = 0; + int err, step; + DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts, + .elem_flags = 0, + .flags = 0, + ); + + xattr.max_entries = max_entries; + map_fd = bpf_create_map_xattr(&xattr); + CHECK(map_fd == -1, + "bpf_create_map_xattr()", "error:%s\n", strerror(errno)); + + keys = malloc(max_entries * sizeof(int)); + values = malloc(max_entries * sizeof(int)); + visited = malloc(max_entries * sizeof(int)); + CHECK(!keys || !values || !visited, "malloc()", "error:%s\n", + strerror(errno)); + + /* populate elements to the map */ + map_batch_update(map_fd, max_entries, keys, values); + + /* test 1: lookup in a loop with various steps. */ + total_success = 0; + for (step = 1; step < max_entries; step++) { + map_batch_update(map_fd, max_entries, keys, values); + map_batch_verify(visited, max_entries, keys, values); + memset(keys, 0, max_entries * sizeof(*keys)); + memset(values, 0, max_entries * sizeof(*values)); + batch = 0; + total = 0; + /* iteratively lookup/delete elements with 'step' + * elements each. + */ + count = step; + nospace_err = false; + while (true) { + err = bpf_map_lookup_batch(map_fd, + total ? &batch : NULL, &batch, + keys + total, + values + total, + &count, &opts); + + CHECK((err && errno != ENOENT), "lookup with steps", + "error: %s\n", strerror(errno)); + + total += count; + if (err) + break; + + } + + if (nospace_err == true) + continue; + + CHECK(total != max_entries, "lookup with steps", + "total = %u, max_entries = %u\n", total, max_entries); + + map_batch_verify(visited, max_entries, keys, values); + + total_success++; + } + + CHECK(total_success == 0, "check total_success", + "unexpected failure\n"); + + printf("%s:PASS\n", __func__); + + free(keys); + free(values); + free(visited); +} diff --git a/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c b/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c new file mode 100644 index 000000000000..976bf415fbdd --- /dev/null +++ b/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ +#include <stdio.h> +#include <errno.h> +#include <string.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +#include <bpf_util.h> +#include <test_maps.h> + +static void map_batch_update(int map_fd, __u32 max_entries, int *keys, + void *values, bool is_pcpu) +{ + typedef BPF_DECLARE_PERCPU(int, value); + value *v = NULL; + int i, j, err; + DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts, + .elem_flags = 0, + .flags = 0, + ); + + if (is_pcpu) + v = (value *)values; + + for (i = 0; i < max_entries; i++) { + keys[i] = i + 1; + if (is_pcpu) + for (j = 0; j < bpf_num_possible_cpus(); j++) + bpf_percpu(v[i], j) = i + 2 + j; + else + ((int *)values)[i] = i + 2; + } + + err = bpf_map_update_batch(map_fd, keys, values, &max_entries, &opts); + CHECK(err, "bpf_map_update_batch()", "error:%s\n", strerror(errno)); +} + +static void map_batch_verify(int *visited, __u32 max_entries, + int *keys, void *values, bool is_pcpu) +{ + typedef BPF_DECLARE_PERCPU(int, value); + value *v = NULL; + int i, j; + + if (is_pcpu) + v = (value *)values; + + memset(visited, 0, max_entries * sizeof(*visited)); + for (i = 0; i < max_entries; i++) { + + if (is_pcpu) { + for (j = 0; j < bpf_num_possible_cpus(); j++) { + CHECK(keys[i] + 1 + j != bpf_percpu(v[i], j), + "key/value checking", + "error: i %d j %d key %d value %d\n", + i, j, keys[i], bpf_percpu(v[i], j)); + } + } else { + CHECK(keys[i] + 1 != ((int *)values)[i], + "key/value checking", + "error: i %d key %d value %d\n", i, keys[i], + ((int *)values)[i]); + } + + visited[i] = 1; + + } + for (i = 0; i < max_entries; i++) { + CHECK(visited[i] != 1, "visited checking", + "error: keys array at index %d missing\n", i); + } +} + +void __test_map_lookup_and_delete_batch(bool is_pcpu) +{ + __u32 batch, count, total, total_success; + typedef BPF_DECLARE_PERCPU(int, value); + int map_fd, *keys, *visited, key; + const __u32 max_entries = 10; + value pcpu_values[max_entries]; + int err, step, value_size; + bool nospace_err; + void *values; + struct bpf_create_map_attr xattr = { + .name = "hash_map", + .map_type = is_pcpu ? BPF_MAP_TYPE_PERCPU_HASH : + BPF_MAP_TYPE_HASH, + .key_size = sizeof(int), + .value_size = sizeof(int), + }; + DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts, + .elem_flags = 0, + .flags = 0, + ); + + xattr.max_entries = max_entries; + map_fd = bpf_create_map_xattr(&xattr); + CHECK(map_fd == -1, + "bpf_create_map_xattr()", "error:%s\n", strerror(errno)); + + value_size = is_pcpu ? sizeof(value) : sizeof(int); + keys = malloc(max_entries * sizeof(int)); + if (is_pcpu) + values = pcpu_values; + else + values = malloc(max_entries * sizeof(int)); + visited = malloc(max_entries * sizeof(int)); + CHECK(!keys || !values || !visited, "malloc()", + "error:%s\n", strerror(errno)); + + /* test 1: lookup/delete an empty hash table, -ENOENT */ + count = max_entries; + err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys, + values, &count, &opts); + CHECK((err && errno != ENOENT), "empty map", + "error: %s\n", strerror(errno)); + + /* populate elements to the map */ + map_batch_update(map_fd, max_entries, keys, values, is_pcpu); + + /* test 2: lookup/delete with count = 0, success */ + count = 0; + err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys, + values, &count, &opts); + CHECK(err, "count = 0", "error: %s\n", strerror(errno)); + + /* test 3: lookup/delete with count = max_entries, success */ + memset(keys, 0, max_entries * sizeof(*keys)); + memset(values, 0, max_entries * value_size); + count = max_entries; + err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys, + values, &count, &opts); + CHECK((err && errno != ENOENT), "count = max_entries", + "error: %s\n", strerror(errno)); + CHECK(count != max_entries, "count = max_entries", + "count = %u, max_entries = %u\n", count, max_entries); + map_batch_verify(visited, max_entries, keys, values, is_pcpu); + + /* bpf_map_get_next_key() should return -ENOENT for an empty map. */ + err = bpf_map_get_next_key(map_fd, NULL, &key); + CHECK(!err, "bpf_map_get_next_key()", "error: %s\n", strerror(errno)); + + /* test 4: lookup/delete in a loop with various steps. */ + total_success = 0; + for (step = 1; step < max_entries; step++) { + map_batch_update(map_fd, max_entries, keys, values, is_pcpu); + memset(keys, 0, max_entries * sizeof(*keys)); + memset(values, 0, max_entries * value_size); + total = 0; + /* iteratively lookup/delete elements with 'step' + * elements each + */ + count = step; + nospace_err = false; + while (true) { + err = bpf_map_lookup_batch(map_fd, + total ? &batch : NULL, + &batch, keys + total, + values + + total * value_size, + &count, &opts); + /* It is possible that we are failing due to buffer size + * not big enough. In such cases, let us just exit and + * go with large steps. Not that a buffer size with + * max_entries should always work. + */ + if (err && errno == ENOSPC) { + nospace_err = true; + break; + } + + CHECK((err && errno != ENOENT), "lookup with steps", + "error: %s\n", strerror(errno)); + + total += count; + if (err) + break; + + } + if (nospace_err == true) + continue; + + CHECK(total != max_entries, "lookup with steps", + "total = %u, max_entries = %u\n", total, max_entries); + map_batch_verify(visited, max_entries, keys, values, is_pcpu); + + total = 0; + count = step; + while (total < max_entries) { + if (max_entries - total < step) + count = max_entries - total; + err = bpf_map_delete_batch(map_fd, + keys + total, + &count, &opts); + CHECK((err && errno != ENOENT), "delete batch", + "error: %s\n", strerror(errno)); + total += count; + if (err) + break; + } + CHECK(total != max_entries, "delete with steps", + "total = %u, max_entries = %u\n", total, max_entries); + + /* check map is empty, errono == ENOENT */ + err = bpf_map_get_next_key(map_fd, NULL, &key); + CHECK(!err || errno != ENOENT, "bpf_map_get_next_key()", + "error: %s\n", strerror(errno)); + + /* iteratively lookup/delete elements with 'step' + * elements each + */ + map_batch_update(map_fd, max_entries, keys, values, is_pcpu); + memset(keys, 0, max_entries * sizeof(*keys)); + memset(values, 0, max_entries * value_size); + total = 0; + count = step; + nospace_err = false; + while (true) { + err = bpf_map_lookup_and_delete_batch(map_fd, + total ? &batch : NULL, + &batch, keys + total, + values + + total * value_size, + &count, &opts); + /* It is possible that we are failing due to buffer size + * not big enough. In such cases, let us just exit and + * go with large steps. Not that a buffer size with + * max_entries should always work. + */ + if (err && errno == ENOSPC) { + nospace_err = true; + break; + } + + CHECK((err && errno != ENOENT), "lookup with steps", + "error: %s\n", strerror(errno)); + + total += count; + if (err) + break; + } + + if (nospace_err == true) + continue; + + CHECK(total != max_entries, "lookup/delete with steps", + "total = %u, max_entries = %u\n", total, max_entries); + + map_batch_verify(visited, max_entries, keys, values, is_pcpu); + err = bpf_map_get_next_key(map_fd, NULL, &key); + CHECK(!err, "bpf_map_get_next_key()", "error: %s\n", + strerror(errno)); + + total_success++; + } + + CHECK(total_success == 0, "check total_success", + "unexpected failure\n"); + free(keys); + free(visited); + if (!is_pcpu) + free(values); +} + +void htab_map_batch_ops(void) +{ + __test_map_lookup_and_delete_batch(false); + printf("test_%s:PASS\n", __func__); +} + +void htab_percpu_map_batch_ops(void) +{ + __test_map_lookup_and_delete_batch(true); + printf("test_%s:PASS\n", __func__); +} + +void test_htab_map_batch_ops(void) +{ + htab_map_batch_ops(); + htab_percpu_map_batch_ops(); +} |