Software Tuning, Performance Optimization & Platform Monitoring
Discussion around monitoring and software tuning methodologies, Performance Monitoring Unit (PMU) of Intel microprocessors, and platform monitoring
This community is designed for sharing of public information. Please do not share Intel or third-party confidential information here.

OFFCORE_RESPONSE_0:OTHER event on Ivy Bridge


I am trying to understand the request type "OTHER" for OFFCORE_RESPONSE_x event (bit 15 of MSR_OFFCORE_RSP_x) on Ivy Bridge (Core i7-3770). Can someone tell me what kind of request types are counted by enabling this bit?

I have written a simple code that allocates a buffer, touches all the elements in the buffer once and then reads all the cachelines in the buffer in a loop:

  buf = (char*) malloc(range*CBSIZE);


  for(counter = 0; counter < 10000; counter ++){
      for(i=0;i<range; i++)
        localbuf = localbuf + (int)buf[i * CBSIZE];

For this piece of code, with buffer size = 64K less which is than L2 size (256 KB), I see almost no L2 Misses (<10K misses out of 10M loads), but the OFFCORE_RESPONSE_0:OTHER:LLC_HITM value is around 4M. The same experiment on Haswell microarchitecture (Core i7 4770) shows no count for OFFCORE_RESPONSE_0:OTHER:LLC_HITM. I am confused as to what is contributing to this event count on Ivy Bridge. Any help would be greatly appreciated.

0 Kudos
0 Replies