microsoft / microsoft/WSL

Consider backporting PMU support for Alder Lake

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Description

Is your feature request related to a problem? Please describe.
There is no PMU driver for the Intel Alder Lake platform. Hardware event sampling does not work with VTune or perf.

vtune -collect hotspots -knob sampling-mode=hw -knob sampling-interval=0.5 /home/trym/source/stud/tdt4186/practical2/build/release/webserver /tmp 8889 12 24
vtune: Error: Unable to perform driverless collection on this platform.
vtune: Error: Cannot enable event-based sampling collection: Architectural Performance Monitoring version is 0. Make sure the vPMU feature is enabled in your hypervisor.
root@DESKTOP-CMKEO60:~# dmesg | grep -i pmu
[    0.177428] Performance Events: unsupported p6 CPU model 151 no PMU driver, software events only.

Describe the solution you'd like
Backport the driver or provide an alternate solution.

Additional context
AFAIK, the only workarounds are to use Hyper-V or dual boot.

https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.13-Perf-Alder-Lake
https://lore.kernel.org/lkml/20210311114814.GA5829@zn.tnic/T/

cpuid.txt

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Open the contributing guide

First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the linked Linux 5.13 perf and LKML discussions, then inspect the reported dmesg output, cpuid.txt, and the VTune/perf failure. Compare the Alder Lake PMU support described there with the behavior in WSL. Done means hardware event sampling works on this platform without the reported unsupported-PMU error.

Written by the indexing model from the issue text.

Assessment

Tech stack
linux
Domain
operating-systems, performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
28/100

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