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μarch bottom up tab has a bad speculation metric that does not match event or summary views

TyL8
Beginner
269 Views

I believe this question has been asked before, but the OP no longer responded:

https://community.intel.com/t5/Analyzers/Weird-result-when-testing-Cinebench2024-and-COMSOL/m-p/1522184/thread-id/23870

 

I am trying to profile PCSX2, a PlayStation 2 emulator. I'm finding that some functions have moderate to high levels of bad speculation due to "Machine Clears."

TyL8_0-1734885024910.png

TyL8_1-1734885048478.png

The summary of my sample shows 0.0% machine clears:

TyL8_2-1734885093727.png

 

More interestingly, I'm reading that there should be three related events

MACHINE_CLEARS.COUNT

MACHINE_CLEARS.MEMORY_ORDERING

MACHINE_CLEARS.SMC

 

I can only find MACHINE_CLEARS.COUNT in the event view and as seen below when sorting by descending order there are a total of 0 machine clears during my entire sample.

TyL8_3-1734885187190.png

 

I have tried the full finalization mode and have invoked VTune finalization from the command line with AMPLXE_SAMPLES_TO_LOAD=0 with no success.

Attached is my entire sample folder zipped.

I would like to know if the machine clears are actually happening, or if I should consider the machine clear metric in the bottom up view to be incorrect.

Note: A reproducible executable might will be difficult to produce, but it's not impossible.


Thanks,
Ty Lamontagne

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1 Solution
yuzhang3_intel
Moderator
201 Views

I am not sure if it is one bug, the platform is too old. But you can customize the uarch-exploration and add the other two related machine clear events for monitoring, try again.

yuzhang3_intel_0-1735000509340.png

 

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2 Replies
yuzhang3_intel
Moderator
202 Views

I am not sure if it is one bug, the platform is too old. But you can customize the uarch-exploration and add the other two related machine clear events for monitoring, try again.

yuzhang3_intel_0-1735000509340.png

 

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TyL8
Beginner
172 Views

Thanks, I totally forgot that you can create your own analysis.

Good news, after enabling those events, and bringing the "Sample After" number way down, I can see the cause of the machine clears.

 

Thanks!

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