perf/x86: Fix low freqency setting issue
Perf doesn't work at low frequencies:
$ perf record -e cpu_core/instructions/ppp -F 120
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument)
for event (cpu_core/instructions/ppp).
"dmesg | grep -i perf" may provide additional information.
The limit_period() check avoids a low sampling period on a counter. It
doesn't intend to limit the frequency.
The check in the x86_pmu_hw_config() should be limited to non-freq mode.
The attr.sample_period and attr.sample_freq are union. The
attr.sample_period should not be used to indicate the frequency mode.
Fixes: c46e665f0377 ("perf/x86: Add INST_RETIRED.ALL workarounds")
Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Ravi Bangoria <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Closes: https://lore.kernel.org/lkml/[email protected]/
1 file changed
