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author | Wang Nan <wangnan0@huawei.com> | 2015-10-14 12:41:20 +0000 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-10-29 17:16:23 -0300 |
commit | d509db0473e40134286271b1d1adadccf42ac467 (patch) | |
tree | e9ec6d2dad1ff0465f2d68edee9e8fcf8c510a62 /tools/perf/tests/bpf-script-example.c | |
parent | 71dc2326252ff1bcdddc05db03c0f831d16c9447 (diff) | |
download | linux-stable-d509db0473e40134286271b1d1adadccf42ac467.tar.gz linux-stable-d509db0473e40134286271b1d1adadccf42ac467.tar.bz2 linux-stable-d509db0473e40134286271b1d1adadccf42ac467.zip |
perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
This patch provides infrastructure for passing source files to --event
directly using:
# perf record --event bpf-file.c command
This patch does following works:
1) Allow passing '.c' file to '--event'. parse_events_load_bpf() is
expanded to allow caller tell it whether the passed file is source
file or object.
2) llvm__compile_bpf() is called to compile the '.c' file, the result
is saved into memory. Use bpf_object__open_buffer() to load the
in-memory object.
Introduces a bpf-script-example.c so we can manually test it:
# perf record --clang-opt "-DLINUX_VERSION_CODE=0x40200" --event ./bpf-script-example.c sleep 1
Note that '--clang-opt' must put before '--event'.
Futher patches will merge it into a testcase so can be tested automatically.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1444826502-49291-10-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/tests/bpf-script-example.c')
-rw-r--r-- | tools/perf/tests/bpf-script-example.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c new file mode 100644 index 000000000000..410a70b93b93 --- /dev/null +++ b/tools/perf/tests/bpf-script-example.c @@ -0,0 +1,44 @@ +#ifndef LINUX_VERSION_CODE +# error Need LINUX_VERSION_CODE +# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' +#endif +#define BPF_ANY 0 +#define BPF_MAP_TYPE_ARRAY 2 +#define BPF_FUNC_map_lookup_elem 1 +#define BPF_FUNC_map_update_elem 2 + +static void *(*bpf_map_lookup_elem)(void *map, void *key) = + (void *) BPF_FUNC_map_lookup_elem; +static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = + (void *) BPF_FUNC_map_update_elem; + +struct bpf_map_def { + unsigned int type; + unsigned int key_size; + unsigned int value_size; + unsigned int max_entries; +}; + +#define SEC(NAME) __attribute__((section(NAME), used)) +struct bpf_map_def SEC("maps") flip_table = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1, +}; + +SEC("func=sys_epoll_pwait") +int bpf_func__sys_epoll_pwait(void *ctx) +{ + int ind =0; + int *flag = bpf_map_lookup_elem(&flip_table, &ind); + int new_flag; + if (!flag) + return 0; + /* flip flag and store back */ + new_flag = !*flag; + bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); + return new_flag; +} +char _license[] SEC("license") = "GPL"; +int _version SEC("version") = LINUX_VERSION_CODE; |