[PATCH v2 bpf-next] libbpf: Use sysconf to simplify libbpf_num_possible_cpus
From: Muhammad Falak R Wani <hidden>
Date: 2021-09-22 07:11:19
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Simplify libbpf_num_possible_cpus by using sysconf(_SC_NPROCESSORS_CONF) instead of parsing a file. This patch is a part ([0]) of libbpf-1.0 milestone. [0] Closes: https://github.com/libbpf/libbpf/issues/383 Signed-off-by: Muhammad Falak R Wani <redacted> --- tools/lib/bpf/libbpf.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ef5db34bf913..f1c0abe5b58d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -10898,25 +10898,16 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz) int libbpf_num_possible_cpus(void) { - static const char *fcpu = "/sys/devices/system/cpu/possible"; static int cpus; - int err, n, i, tmp_cpus; - bool *mask; + int tmp_cpus; tmp_cpus = READ_ONCE(cpus); if (tmp_cpus > 0) return tmp_cpus; - err = parse_cpu_mask_file(fcpu, &mask, &n); - if (err) - return libbpf_err(err); - - tmp_cpus = 0; - for (i = 0; i < n; i++) { - if (mask[i]) - tmp_cpus++; - } - free(mask); + tmp_cpus = sysconf(_SC_NPROCESSORS_CONF); + if (tmp_cpus < 1) + return libbpf_err(-EINVAL); WRITE_ONCE(cpus, tmp_cpus); return tmp_cpus;
--
2.17.1