• Aneesh Kumar K.V's avatar
    powerpc/mm: Add trace point for tracking hash pte fault · cfcb3d80
    Aneesh Kumar K.V authored
    This enables us to understand how many hash fault we are taking
    when running benchmarks.
    
    For ex:
    -bash-4.2# ./perf stat -e  powerpc:hash_fault -e page-faults /tmp/ebizzy.ppc64 -S 30  -P -n 1000
    ...
    
     Performance counter stats for '/tmp/ebizzy.ppc64 -S 30 -P -n 1000':
    
           1,10,04,075      powerpc:hash_fault
           1,10,03,429      page-faults
    
          30.865978991 seconds time elapsed
    
    NOTE:
    The impact of the tracepoint was not noticeable when running test. It was
    within the run-time variance of the test. For ex:
    
    without-patch:
    --------------
    
     Performance counter stats for './a.out 3000 300':
    
    	       643      page-faults               #    0.089 M/sec
    	  7.236562      task-clock (msec)         #    0.928 CPUs utilized
    	 2,179,213      stalled-cycles-frontend   #    0.00% frontend cycles idle
    	17,174,367      stalled-cycles-backend    #    0.00% backend  cycles idle
    		 0      context-switches          #    0.000 K/sec
    
           0.007794658 seconds time elapsed
    
    And with-patch:
    ---------------
    
     Performance counter stats for './a.out 3000 300':
    
    	       643      page-faults               #    0.089 M/sec
    	  7.233746      task-clock (msec)         #    0.921 CPUs utilized
    		 0      context-switches          #    0.000 K/sec
    
           0.007854876 seconds time elapsed
    
     Performance counter stats for './a.out 3000 300':
    
    	       643      page-faults               #    0.087 M/sec
    	       649      powerpc:hash_fault        #    0.087 M/sec
    	  7.430376      task-clock (msec)         #    0.938 CPUs utilized
    	 2,347,174      stalled-cycles-frontend   #    0.00% frontend cycles idle
    	17,524,282      stalled-cycles-backend    #    0.00% backend  cycles idle
    		 0      context-switches          #    0.000 K/sec
    
           0.007920284 seconds time elapsed
    Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    cfcb3d80
trace.h 3.22 KB