topic Dear Peter, in Analyzers

Hardware event construction

Hanqing_H_ — Tue, 26 Mar 2013 16:37:24 GMT

Sorry to ask a stupid question. We have a 4P Intel Xeon E5-4620 CPU (Sandy Bridge), and we want to use vtune to moniter some hardware events in the packege. Our motherboard is Dell R720. So, where can we get the events that can be sampled with vtune-update5? I have seen a list in the last section of http://software.intel.com/sites/products/documentation/doclib/stdxe/2013...

But a lot of events that claimed to be supported in Xeon processors cannot be sampled. For example, when run

amplxe-cl -collect-with runsa -knob event-config="SNOOP_RESPONSE.HIT" ls -alrt

I get

amplxe: Error: Invalid Event SNOOP_RESPONSE.HIT discarded.

However, I succeeded once with "OFFCORE_RESPONSE.PF_L2_DATA_RD.LLC_MISS.ANY_RESPONSE_0" event. But I have tried several others and get the same "invaild event" response, like OFFCORE_RESPONSE_0.DATA_IFETCH.LLC_MISS_LOCAL_DRAM, MEM_LOAD_UOPS_MISC_RETIRED.LLC_MISS etc.

The purpose of my test is to using "OFFCORE_RESPONSE_0" with snoop filter to moniter the snoop traffic between CPUs. The method to sample OFFCORE_RESPONSE_0 event is as section 18.8.5 in http://download.intel.com/products/processor/manual/325462.pdf

But what is way to utilize this method in vtune?

I also made sure that there was only one instance of vtune running in the system. So where can we get the valid event list or how can we construct the righ event for moniter?

Thanks a lot!

The doc you referenced is for

Peter_W_Intel — Wed, 27 Mar 2013 01:26:02 GMT

The doc you referenced is for general description of structural event list for Intel(R) Core(TM) processors.

Some events name are "basic" or some are "unique" for different processors. You'd better check supported events in your system, by using:

amplxe-runss -event-list

Dear Peter,

Hanqing_H_ — Wed, 27 Mar 2013 16:14:53 GMT

Dear Peter,

Thanks a lot. That is exactly what I need.

Peter Wang (Intel) wrote:

The doc you referenced is for general description of structural event list for Intel(R) Core(TM) processors.

Some events name are "basic" or some are "unique" for different processors. You'd better check supported events in your system, by using:

amplxe-runss -event-list

Additionally, probably the

Shannon_C_Intel — Wed, 27 Mar 2013 16:31:17 GMT

Additionally, probably the best events to use for monitoring traffic between sockets are:

OFFCORE_RESPONSE.DEMAND_DATA_RD.LLC_MISS.REMOTE_HIT_FORWARD_0/1, OFFCORE_RESPONSE.DEMAND_DATA_RD.LLC_MISS.REMOTE_HITM_0/1.

These include true demand reads, as well as L1 hardware prefetches. Unfortunately there are no OFFCORE_RESPONSE events that do not also get triggered by L1 hardware prefetches, so these are the best choice.