On 17-Jan-25 8:49 PM, kan.liang@linux.intel.com wrote:
From: Kan Liang kan.liang@linux.intel.com
Perf doesn't work with a low freq.
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 freq mode.
Fixes: c46e665f0377 ("perf/x86: Add INST_RETIRED.ALL workarounds") Closes: https://lore.kernel.org/lkml/20250115154949.3147-1-ravi.bangoria@amd.com/ Signed-off-by: Kan Liang kan.liang@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Ravi Bangoria ravi.bangoria@amd.com Cc: stable@vger.kernel.org
Reviewed-by: Ravi Bangoria ravi.bangoria@amd.com
Thanks, Ravi