Enabling hardware counter profiling

[stammler]

I encountered an issue when trying to do hardware counter profiling with gprofng. There is already a similar closed issue but I am not sure if this is related to my problem.

When running gprofng I get:

~$ gprofng collect app -h
Run "x86_64-linux-gnu-gprofng collect app --help" for a usage message.
HW counter profiling is not supported on this system

I'm on WSL2

~$ uname -r
5.15.167.4-microsoft-standard-WSL2

with Ubuntu:

~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 24.04.2 LTS
Release:        24.04
Codename:       noble

My processor is a Intel Core Ultra 7 155H

~$ cat /proc/cpuinfo | grep "model name" | head -1
model name      : Intel(R) Core(TM) Ultra 7 155H

I installed perf from source and it seems to be working generally, but I don't think I have hardware events available:

~$ perf list
List of pre-defined events (to be used in -e or -M):

  alignment-faults                                   [Software event]
  bpf-output                                         [Software event]
  cgroup-switches                                    [Software event]
  context-switches OR cs                             [Software event]
  cpu-clock                                          [Software event]
  cpu-migrations OR migrations                       [Software event]
  dummy                                              [Software event]
  emulation-faults                                   [Software event]
  major-faults                                       [Software event]
  minor-faults                                       [Software event]
  page-faults OR faults                              [Software event]
  task-clock                                         [Software event]

tool:
  duration_time
  user_time
  system_time
  msr/tsc/                                           [Kernel PMU event]
  rNNN                                               [Raw hardware event descriptor]
  cpu/t1=v1[,t2=v2,t3 ...]/modifier                  [Raw hardware event descriptor]
       [(see 'man perf-list' on how to encode it)]
  mem:<addr>[/len][:access]                          [Hardware breakpoint]
Error: failed to open tracing events directory

I also get the following message:

~$ dmesg | grep PMU
[    0.128659] Performance Events: unsupported p6 CPU model 170 no PMU driver, software events only.

Is there a way how I can turn on hardware counter pofiling or is there a general problem with my system?

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[stammler]

/question

[github-actions[bot]]

Diagnostic information

Found '/question', adding tag 'question'

[craigloewen-msft]

Could you try running wsl --update --pre-release to get to the latest WSL version, and then try and run the dmesg | grep PMU command again? I'm curious if kernel modules will help address this.

[elsaco]

Performance Events: PMU not available due to virtualization, using software events only

Kernel 6.6.84.1-microsoft-standard-WSL2 and WSL version 2.5.6

[stammler]

After wsl --update --pre-release I am at

~$ uname -r
6.6.84.1-microsoft-standard-WSL2

But I still only have software events:

~$ dmesg | grep PMU
[    0.062006] Performance Events: unsupported p6 CPU model 183 no PMU driver, software events only.
[    0.134691] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer

Just curious, should perf be part of the pre-release?
Because right now it isn't present on my system and I have to build it from source again.

[lwintermelon]

See discussions here, they found that vm in hyper-v can support PMU, but wsl2 not.

I test 3 computers for wsl2 performance counters support, intel i5-11400 and amd r5-5600u are both OK, only the one with intel i9-12900H fails.

[clemenswasser]

@craigloewen-msft This is a duplicate of #8155. TL;DR: For Alderlake CPUs and later, Linux requires the arch_perfmon CPU feature to be available for supporting PMU. Hyper-V supports this, but HCS and therefore also WSL for some reason don't support it. In theory, HCS also supports enabling perfmon features like Hyper-V, but when enabling any of them the VM creation fails for me with an error saying that enabling the feature is not supported.

[stammler]

Thank you! So that means right now that is expected behavior and there's nothing I could do except not using WSL?