Performance counters on Ampere eMAG
John F Carr <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.arm |
|---|---|
| Message-ID | <[email protected]> |
Is anybody successfully using performance counters on ARM eMAG? I am getting bad counts from pmcstat -p.
Example:
# pmcstat -p cpu_cycles -p wait_cycles -p exc_svc echo \\c
# p/cpu_cycles p/wait_cycles p/exc_svc
4298795386 0 47
# pmcstat -p cpu_cycles -p wait_cycles -p exc_svc echo \\c
# p/cpu_cycles p/wait_cycles p/exc_svc
3806520 4294967296 4294967343
The large numbers may be 0x100000000 (2^32) greater than the correct numbers.
I am running 14.2-STABLE. Cortex A57 and A72 running CURRENT work fine.
John Carr