From: Tonghao Zhang <tong@xxxxxxxxxxxxx>
The number of online cpu may be not equal to possible cpu.
bpftool prog profile, can not create pmu event on possible
but not online cpu.
$ dmidecode -s system-product-name
PowerEdge R620
$ cat /sys/devices/system/cpu/online
0-31
$ cat /sys/devices/system/cpu/possible
0-47
To fix this issue, use online cpu instead of possible, to
create perf event and other resource.
Signed-off-by: Tonghao Zhang <tong@xxxxxxxxxxxxx>
Cc: Quentin Monnet <quentin@xxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Yonghong Song <yhs@xxxxxx>
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: KP Singh <kpsingh@xxxxxxxxxx>
Cc: Stanislav Fomichev <sdf@xxxxxxxxxx>
Cc: Hao Luo <haoluo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/bpf/bpftool/prog.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index cfc9fdc1e863..08b352dd799e 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -2056,6 +2056,7 @@ static int profile_parse_metrics(int argc, char **argv)
static void profile_read_values(struct profiler_bpf *obj)
{
+ __u32 possible_cpus = libbpf_num_possible_cpus();
__u32 m, cpu, num_cpu = obj->rodata->num_cpu;
int reading_map_fd, count_map_fd;
__u64 counts[num_cpu];
@@ -2080,7 +2081,7 @@ static void profile_read_values(struct profiler_bpf *obj)
profile_total_count += counts[cpu];
for (m = 0; m < ARRAY_SIZE(metrics); m++) {
- struct bpf_perf_event_value values[num_cpu];
+ struct bpf_perf_event_value values[possible_cpus];
if (!metrics[m].selected)
continue;
@@ -2321,7 +2322,7 @@ static int do_profile(int argc, char **argv)
if (num_metric <= 0)
goto out;
- num_cpu = libbpf_num_possible_cpus();
+ num_cpu = libbpf_num_online_cpus();
if (num_cpu <= 0) {
p_err("failed to identify number of CPUs");
goto out;
--
2.27.0
