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what's the difference between Instructions Retired and Retiring?

seung_hoe_cho
Beginner
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화면 캡처 2022-10-28 164751.jpg

I get this result in virtual machine. Retiring is not 0, 28.8% but Instruction Retired is 0. Are those two items different?

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JyothisV_Intel
Moderator
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Hi,

 

Good day to you.

 

Thanks for posting in Intel Communities.

 

Instructions Retired is an important hardware performance event that shows how many instructions were completely executed. Modern processors execute much more instructions that the program flow needs. This is called a speculative execution. Instructions that were "proven" as indeed needed by the program execution flow are "retired".

 

Reference: https://www.intel.com/content/www/us/en/develop/documentation/vtune-help/top/analyze-performance/custom-analysis/custom-analysis-options/hardware-event-list/instructions-retired-event.html

 

Retiring metric represents a pipeline slots fraction utilized by useful work, meaning the issued uOps that eventually get retired. Ideally, all Pipeline Slots would be attributed to the Retiring category. Retiring of 100% would indicate the maximum possible number of uOps retired per cycle has been achieved. Maximizing Retiring typically increases the Instruction-Per-Cycle metric. Note that a high Retiring value does not necessarily mean no more room for performance improvement.

 

Reference: https://www.intel.com/content/www/us/en/develop/documentation/vtune-help/top/reference/cpu-metrics-reference.html#cpu-metrics-reference_RETIRING

 

Since you are running VTune inside a VM, certain metrics might not be collected correctly due to lesser access to hardware counters. Can you get back to us with the following information so that we can assist you better.

 

1. Host OS and Guest OS (VM)

2. Sample Code/Binary used for VTune analysis inside the VM

3. The exact steps followed by you to perform the analysis

4. Output of the following commands:

 

$ sudo <vtune-install-dir>/sepdk/src/insmod-sep -r

$ sudo <vtune-install-dir>/sepdk/src/insmod-sep -q

$ sudo <vtune-install-dir>/bin64/vtune-self-checker.sh

 

Eg.:

sudo /opt/intel/oneapi/vtune/latest/sepdk/src/insmod-sep -r
sudo /opt/intel/oneapi/vtune/latest/sepdk/src/insmod-sep -q
sudo /opt/intel/oneapi/vtune/latest/bin64/vtune-self-checker.sh

 

Regards,

Jyothis V James

 

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seung_hoe_cho
Beginner
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Thanks a lot!

Sry for late..

1. Host OS: Window 11, Guest OS : ubuntu

2. Spec cpu 2006 bzip2, attach the tar file

3. Execute gui(vtune-gui) -> Application parameters : input program 10 microarchitecture exploration, others are defalut

4. I delete vtune because of storage problem, I can't get results from those commands. Above results are based on my memory.

Best regards

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JyothisV_Intel
Moderator
636 Views

Hi,

 

Good day to you.

 

Apologies for the delay in getting back to you.

 

We tried running Micro-architecture analysis after compiling the code provided by you and was able to successfully perform the analysis

 

JyothisV_Intel_0-1670428427870.png

 

Our test scenario is given below:

Host OS: Windows 11 Pro 22H2

Guest OS: Ubuntu 22.04 LTS

Hypervisor: Hyper-V with IPT and PMU enabled

Hyper-V Configuration Version: 9.2

Processor: Intel(R) Core(TM) i7-8665U CPU @ 1.90GHz 2.11 GHz

 

(Please find the attached results)

 

To make sure that all performance metrices are collected while running the analysis inside a VM, it is recommended to enable PMU for the VM. Unfortunately, since you deleted the VM, we are not sure if all flags and privileges were provided to VM so that it can log hardware events. This might have causes the issues that you observed The data collected inside the VM might not be reliable due to this. It is recommended to perform VTune profiling inside the Host OS rather than inside a VM for better accurate profiling.

 

If this answers your question, please click the “Accept as Solution” button to indicate your issue is resolved.

 

Thanks and Regards,

Jyothis V James

 

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JyothisV_Intel
Moderator
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Hi,


Good day to you.


We have not received any response from you. Intel will no longer monitor this thread. If you need further assistance, please post a new question.


Thanks and Regards,

Jyothis V James


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