topic vtune memory-access report showing incorrect output in Analyzers

vtune memory-access report showing incorrect output

Naveedcharlow — Thu, 21 Apr 2022 17:01:57 GMT

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?

Re:vtune memory-access report showing incorrect output

JaideepK_Intel — Fri, 22 Apr 2022 14:04:36 GMT

Hi,

Thank you for posting in Intel Communities.

Please can you answer the following questions:

1. What is the version of Intel® Vtune that you are using?

2. Please can you share your O.S and processor details?

3. Please can you share the exact steps you followed and a sample reproducer(sample application that is similar to the application you are trying to analyze)?

Thank You,

Jaideep

Re:vtune memory-access report showing incorrect output

JaideepK_Intel — Wed, 27 Apr 2022 08:29:46 GMT

Hi,

Can you please share the details which are mentioned below?

Thanks,

Jaideep

Re:vtune memory-access report showing incorrect output

JaideepK_Intel — Wed, 04 May 2022 13:12:31 GMT

Hi,

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.

Thanks,

Jaideep

Re:vtune memory-access report showing incorrect output

JaideepK_Intel — Wed, 11 May 2022 08:34:39 GMT

Hi,

If this resolves your issue, make sure to accept this as a solution. This would help others with similar issue. Thank you!

Thanks,

Jaideep

Re:vtune memory-access report showing incorrect output

JaideepK_Intel — Wed, 18 May 2022 04:57:29 GMT

Hi,

We assume that your issue is resolved. If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.

Thanks,

Jaideep