2020-06-29 19:27:35

by Prarit Bhargava

[permalink] [raw]
Subject: [PATCH] turbostat: Use sched_getcpu() instead of hardcoded cpu 0

Disabling cpu 0 results in an error

turbostat: /sys/devices/system/cpu/cpu0/topology/thread_siblings: open failed: No such file or directory

Use sched_getcpu() instead of a hardcoded cpu 0 to get the max cpu number.

Signed-off-by: Prarit Bhargava <[email protected]>
Cc: Len Brown <[email protected]>
Cc: [email protected]
Cc: Srinivas Pandruvada <[email protected]>
---
tools/power/x86/turbostat/turbostat.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 33b370865d16..2d3a3012f2f8 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -2769,12 +2769,19 @@ void re_initialize(void)
void set_max_cpu_num(void)
{
FILE *filep;
+ int base_cpu;
unsigned long dummy;
+ char pathname[64];

+ base_cpu = sched_getcpu();
+ if (base_cpu < 0)
+ err(1, "cannot find calling cpu ID");
+ sprintf(pathname,
+ "/sys/devices/system/cpu/cpu%d/topology/thread_siblings",
+ base_cpu);
+
+ filep = fopen_or_die(pathname, "r");
topo.max_cpu_num = 0;
- filep = fopen_or_die(
- "/sys/devices/system/cpu/cpu0/topology/thread_siblings",
- "r");
while (fscanf(filep, "%lx,", &dummy) == 1)
topo.max_cpu_num += BITMASK_SIZE;
fclose(filep);
--
2.21.3