Software Tuning, Performance Optimization & Platform Monitoring
Discussion regarding monitoring and software tuning methodologies, Performance Monitoring Unit (PMU) of Intel microprocessors, and platform updating.

BTS not generating interrupt


I am working on BTS implementation in Linux driver.

My BTS code is not generating any interrupt after crossing the threshold in debug store. Though the Counting method generates interrupt.

So, I combined BTS and Counting methods. Inside the interrupt handler (interrupt generated when IA32_PMC0 reaches 0), I can see the BTS Debug Store contents through ioctl.

I was wondering if somebody could help me understand why is BTS not generating interrupts?

Quick setup information:

IA32_DS_AREA contains the debug store address.

IA32_PMC0 contains the period value.

PerfEvtSel0 contains the event  tracking in user mode, generating interrupt and is enabled.

LBR_SELECT contains branch info I want to track.

IA32_DEBUGCTL has BTINT, BTS, TR bits enabled.

Am I missing any step?

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