On Sun, Feb 19, 2017 at 01:28:34AM +0530, Madhavan Srinivasan wrote: > From PowerISA v2.07, architecture provides a special NOP > instruction called "Probe-Nop" defined as "and 0,0,0". > This form of "and" is reserved for use exclusively by the > Performance Monitor. > > Usage example: > > Add PROBENOP() macro to __tlbie() in hash_native_64.c to > verify the number of TLBIE. Power8 provides "PM_TLBIE_FIN" > PMU event (r30058) to count "tlbie finished". > > Power8 PMU event "PM_PROBE_NOP_DISP" (r40014) counts the > "ProbeNops dispatched". > > With modified kernel booted, output from perf: > > # ./perf stat -e r30058,r40014 ls > .... > Performance counter stats for 'ls': > > 7 r30058 > 7 r40014 > > 0.003296959 seconds time elapsed > > Macro comes handy when want to count specific instructions > which may or may not have a PMU event. > > Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> > ---
Acked-by: Balbir Singh <bsinghar...@gmail.com>
