Permissions
On some systems, using Perf hardware counters can be restricted by the value of /proc/sys/kernel/perf_event_paranoid
.
perf_event_paranoid |
Description |
---|---|
3 |
Disable use of Perf events |
2 |
Allow only user-space measurements |
1 |
Allow kernel and user-space measurements |
0 |
Allow access to CPU-specific data, but not raw trace‐point samples. |
-1 |
No restrictions |
The value of /proc/sys/kernel/perf_event_paranoid
must be 2 or lower to collect Perf metrics. To set this until the next reboot, run the following commands:
sudo sysctl -w kernel.perf_event_paranoid=2
To permanently set the paranoid level, add the following line to /etc/sysctl.conf
:
kernel.perf_event_paranoid=2