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author | Mike Marshall <hubcap@omnibond.com> | 2015-11-16 18:58:57 +0300 |
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committer | Mike Marshall <hubcap@omnibond.com> | 2015-11-16 18:58:57 +0300 |
commit | a52079dad4718fa924ae81a939f8a665366f562b (patch) | |
tree | a9d6004f9bf1beff49cbfe0d5bf6edbf621b065d /tools/perf/tests/bpf-script-example.c | |
parent | 24c8d0804be00da90af9efa8eb404bd7a3284ba9 (diff) | |
parent | 8005c49d9aea74d382f474ce11afbbc7d7130bec (diff) | |
download | linux-a52079dad4718fa924ae81a939f8a665366f562b.tar.xz |
Orangefs: Merge tag 'v4.4-rc1' into for-next
Linux 4.4-rc1
Diffstat (limited to 'tools/perf/tests/bpf-script-example.c')
-rw-r--r-- | tools/perf/tests/bpf-script-example.c | 48 |
1 files changed, 48 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..0ec9c2c03164 --- /dev/null +++ b/tools/perf/tests/bpf-script-example.c @@ -0,0 +1,48 @@ +/* + * bpf-script-example.c + * Test basic LLVM building + */ +#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; |