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| author | Wang Nan <wangnan0@huawei.com> | 2015-11-04 14:20:04 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-11-05 18:47:02 +0300 |
| commit | 59f41af980f95cbd556a6dc2e064b412abc439cf (patch) | |
| tree | 275d7385bf1a1e5d0ca91aa4e2295568aeff5874 /tools | |
| parent | 98916392a0bdfd71668b711fd93915791f45df02 (diff) | |
| download | linux-59f41af980f95cbd556a6dc2e064b412abc439cf.tar.xz | |
perf llvm: Pass number of configured CPUs to clang compiler
This patch introduces a new macro "__NR_CPUS__" to perf's embedded clang
compiler, which represent the number of configured CPUs in this system.
BPF programs can use this macro to create a map with the same number of
system CPUs. For example:
struct bpf_map_def SEC("maps") pmu_map = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = __NR_CPUS__,
};
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446636007-239722-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/llvm-utils.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 4f6a4780bd5f..80eecefc604f 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -11,10 +11,11 @@ #include "cache.h" #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \ - "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS " \ - "$KERNEL_INC_OPTIONS -Wno-unused-value " \ - "-Wno-pointer-sign -working-directory " \ - "$WORKING_DIR -c \"$CLANG_SOURCE\" -target bpf -O2 -o -" + "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\ + "$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \ + "-Wno-unused-value -Wno-pointer-sign " \ + "-working-directory $WORKING_DIR " \ + "-c \"$CLANG_SOURCE\" -target bpf -O2 -o -" struct llvm_param llvm_param = { .clang_path = "clang", @@ -326,8 +327,8 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts) int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { - int err; - char clang_path[PATH_MAX]; + int err, nr_cpus_avail; + char clang_path[PATH_MAX], nr_cpus_avail_str[64]; const char *clang_opt = llvm_param.clang_opt; const char *template = llvm_param.clang_bpf_cmd_template; char *kbuild_dir = NULL, *kbuild_include_opts = NULL; @@ -354,6 +355,17 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, */ get_kbuild_opts(&kbuild_dir, &kbuild_include_opts); + nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF); + if (nr_cpus_avail <= 0) { + pr_err( +"WARNING:\tunable to get available CPUs in this system: %s\n" +" \tUse 128 instead.\n", strerror(errno)); + nr_cpus_avail = 128; + } + snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d", + nr_cpus_avail); + + force_set_env("NR_CPUS", nr_cpus_avail_str); force_set_env("CLANG_EXEC", clang_path); force_set_env("CLANG_OPTIONS", clang_opt); force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts); |