I am running vtune -collect memory-access ./main
and I receive the output below. The main
binary does a lot of random memory accesses on a large virtual and physical memory range.
Memory Bound
LLC Miss: 0.0% of Clockticks
DRAM Bandwidth Bound: 0.0% of Elapsed Time
LLC Miss Count: 0
Average Latency (cycles): 19
Total Thread Count: 2
Paused Time: 0s
The input seems incorrect since there are actually many LLC misses, and the uarch-exploration
report shows a 100% LLC replacement percentage (though the 100% result seems incorrect, too). On the other hand, other stats outputted by the uarch-exploration
report (e.g., CPI rate) seem reasonable. Is there something I need to do to get vtune to work correctly? Is it possible that maybe vtune just does not fully support my CPU version and so only some of its features work?
Vtune shows this kind of output only when an executable runs in negligible time or if there is some issue with your executable. Please make sure that there are no issues while running your executable.