When I test the Multi_core event BUS_HITM_DRV with vtune, I get the event BUS_HITM_DRV.THIS_AGENT is far lower than BUS_HITM_DRV.ALL_AGENTS.(about 1/2 of it)
And I think it shouldn't be that according to the explain which vtune guide gives about ALL_AGENTS and THIS_AGENT as follows:
THIS_AGENT:Counts bus transactions initiated by this bus agent only.
ALL_AGENTS:Counts bus transactions initiated by any agent on the bus. In systems where each processor is attached to a different bus, each core counts only events it sees on its own bus.
Ifsomeoneknows something about this, please help me.
Thank you very much!
anshgm:it is not clear on what system you measure. in a quad core system this makes sense. however you can use EXT_SNOOP.THIS_AGENT.HITM to count modified data sharing.
My system has two 5310 processor, which is included in the Intel Core 2 Duo Processor. Each 5310 has four core, and each core has one L1 data cache and one L1 instruction cache. And every two cores share a L2 cache.