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author | Alexei Starovoitov <ast@kernel.org> | 2020-05-01 20:36:32 +0300 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-01 20:37:34 +0300 |
commit | 3dbb5b5040c396274a253b607289748f39a680a0 (patch) | |
tree | 6b010c99c159d08a48680e709ca37e3fe3e17971 /tools | |
parent | c321022244708aec4675de4f032ef1ba9ff0c640 (diff) | |
parent | 31a9f7fe93378ab587d758d5b2e96a237caa7b8c (diff) | |
download | linux-3dbb5b5040c396274a253b607289748f39a680a0.tar.xz |
Merge branch 'bpf_enable_stats'
Song Liu says:
====================
run_time_ns is a useful stats for BPF programs. However, it is gated by
sysctl kernel.bpf_stats_enabled. When multiple user space tools are
toggling kernl.bpf_stats_enabled at the same time, they may confuse each
other.
Solve this problem with a new BPF command BPF_ENABLE_STATS.
Changes v8 => v9:
1. Clean up in selftest (Andrii).
2. Not using static variable in test program (Andrii).
Changes v7 => v8:
1. Change name BPF_STATS_RUNTIME_CNT => BPF_STATS_RUN_TIME (Alexei).
2. Add CHECK_ATTR to bpf_enable_stats() (Alexei).
3. Rebase (Andrii).
4. Simplfy the selftest (Alexei).
Changes v6 => v7:
1. Add test to verify run_cnt matches count measured by the program.
Changes v5 => v6:
1. Simplify test program (Yonghong).
2. Rebase (with some conflicts).
Changes v4 => v5:
1. Use memset to zero bpf_attr in bpf_enable_stats() (Andrii).
Changes v3 => v4:
1. Add libbpf support and selftest;
2. Avoid cleaning trailing space.
Changes v2 => v3:
1. Rename the command to BPF_ENABLE_STATS, and make it extendible.
2. fix commit log;
3. remove unnecessary headers.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/include/uapi/linux/bpf.h | 11 | ||||
-rw-r--r-- | tools/lib/bpf/bpf.c | 10 | ||||
-rw-r--r-- | tools/lib/bpf/bpf.h | 1 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.map | 1 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/enable_stats.c | 45 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_enable_stats.c | 18 |
6 files changed, 86 insertions, 0 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 0eccafae55bb..705e4822f997 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -115,6 +115,7 @@ enum bpf_cmd { BPF_LINK_UPDATE, BPF_LINK_GET_FD_BY_ID, BPF_LINK_GET_NEXT_ID, + BPF_ENABLE_STATS, }; enum bpf_map_type { @@ -390,6 +391,12 @@ enum { */ #define BPF_F_QUERY_EFFECTIVE (1U << 0) +/* type for BPF_ENABLE_STATS */ +enum bpf_stats_type { + /* enabled run_time_ns and run_cnt */ + BPF_STATS_RUN_TIME = 0, +}; + enum bpf_stack_build_id_status { /* user space need an empty entry to identify end of a trace */ BPF_STACK_BUILD_ID_EMPTY = 0, @@ -601,6 +608,10 @@ union bpf_attr { __u32 old_prog_fd; } link_update; + struct { /* struct used by BPF_ENABLE_STATS command */ + __u32 type; + } enable_stats; + } __attribute__((aligned(8))); /* The description below is an attempt at providing documentation to eBPF diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 8f2f0958d446..43322f0d6c7f 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -841,3 +841,13 @@ int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, return err; } + +int bpf_enable_stats(enum bpf_stats_type type) +{ + union bpf_attr attr; + + memset(&attr, 0, sizeof(attr)); + attr.enable_stats.type = type; + + return sys_bpf(BPF_ENABLE_STATS, &attr, sizeof(attr)); +} diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 335b457b3a25..1901b2777854 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -231,6 +231,7 @@ LIBBPF_API int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, __u64 *probe_addr); +LIBBPF_API int bpf_enable_stats(enum bpf_stats_type type); #ifdef __cplusplus } /* extern "C" */ diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 7cd49aa38005..e03bd4db827e 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -257,6 +257,7 @@ LIBBPF_0.0.8 { LIBBPF_0.0.9 { global: + bpf_enable_stats; bpf_link_get_fd_by_id; bpf_link_get_next_id; } LIBBPF_0.0.8; diff --git a/tools/testing/selftests/bpf/prog_tests/enable_stats.c b/tools/testing/selftests/bpf/prog_tests/enable_stats.c new file mode 100644 index 000000000000..2cb2085917e7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/enable_stats.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "test_enable_stats.skel.h" + +void test_enable_stats(void) +{ + struct test_enable_stats *skel; + int stats_fd, err, prog_fd; + struct bpf_prog_info info; + __u32 info_len = sizeof(info); + int duration = 0; + + skel = test_enable_stats__open_and_load(); + if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) + return; + + stats_fd = bpf_enable_stats(BPF_STATS_RUN_TIME); + if (CHECK(stats_fd < 0, "get_stats_fd", "failed %d\n", errno)) { + test_enable_stats__destroy(skel); + return; + } + + err = test_enable_stats__attach(skel); + if (CHECK(err, "attach_raw_tp", "err %d\n", err)) + goto cleanup; + + test_enable_stats__detach(skel); + + prog_fd = bpf_program__fd(skel->progs.test_enable_stats); + memset(&info, 0, info_len); + err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); + if (CHECK(err, "get_prog_info", + "failed to get bpf_prog_info for fd %d\n", prog_fd)) + goto cleanup; + if (CHECK(info.run_time_ns == 0, "check_stats_enabled", + "failed to enable run_time_ns stats\n")) + goto cleanup; + + CHECK(info.run_cnt != skel->bss->count, "check_run_cnt_valid", + "invalid run_cnt stats\n"); + +cleanup: + test_enable_stats__destroy(skel); + close(stats_fd); +} diff --git a/tools/testing/selftests/bpf/progs/test_enable_stats.c b/tools/testing/selftests/bpf/progs/test_enable_stats.c new file mode 100644 index 000000000000..01a002ade529 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_enable_stats.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include <linux/bpf.h> +#include <stdint.h> +#include <linux/types.h> +#include <bpf/bpf_helpers.h> + +char _license[] SEC("license") = "GPL"; + +__u64 count = 0; + +SEC("raw_tracepoint/sys_enter") +int test_enable_stats(void *ctx) +{ + count += 1; + return 0; +} |