CODEWITHSUNDEEP
linuxwindows-subsystem-for-linuxperf
yodahaji
yodahaji

Reputation: 887

Is there any method to run perf under WSL?

When I wanted to run perf under WSL, I met the follow question:

WARNING: perf not found for kernel 4.4.0-18362

You may need to install the following packages for this specific kernel:

linux-tools-4.4.0-18362-Microsoft

linux-cloud-tools-4.4.0-18362-Microsoft

You may also want to install one of the following packages to keep up to date:

linux-tools-Microsoft

linux-cloud-tools-Microsoft

But I can't find packages called linux-tools-4.4.0-18362-Microsoft or linux-cloud-tools-4.4.0-18362-Microsoft. I guess the package names are generated automatically.

I also tried to use perf in docker container. However, docker container use the same kernel as the hosts.

Is there any method to run perf under WSL?

I heard that perf can be used in WSL2. But after I upgraded to WSL2, it shows the similar error message:

WARNING: perf not found for kernel 4.19.84-microsoft

You may need to install the following packages for this specific kernel:

linux-tools-4.19.84-microsoft-standard

linux-cloud-tools-4.19.84-microsoft-standard

You may also want to install one of the following packages to keep up to date:

linux-tools-standard

linux-cloud-tools-standard

Upvotes: 60

Views: 43459

Answers (7)

L. Teder
L. Teder

Reputation: 1045

In my case (WSL2 Debian), I fixed this by installing linux-perf. It was after trying a couple answers here and reading this WSL Issue.

Upvotes: 0

Sergey Kolesnik
Sergey Kolesnik

Reputation: 3650

I have experienced an error when trying to run perf stat using both the compiled and linux-tools-generic versions:

./perf stat -d ls
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (slots:u).
/bin/dmesg | grep -i perf may provide additional information.

Any rituals for updating/enabling/disable WSL2 or reinstalling Ubuntu image didn't fix it.
I have found an explanation in some newsletter:

Add [email protected] as this issue is in virtualization env.

The topdown metrics events became default since commit 42641d6f4d15 ("perf stat: Add Topdown metrics events as default events"). The perf will use 'slots' if the /sys/bus/event_source/devices/cpu/events/slots is available.

Unfortunately, the 'slots' may not be supported in the virualization environment. The hypervisor may not expose the 'slots' counter to the VM in cpuid. As a result, the kernel may disable topdown slots and metrics events in intel_pmu_init() if slots event is not in CPUID. E.g., both c->weight and c->idxmsk64 are set to 0.

There will be below error on Icelake VM since 'slots' is the leader:

$ perf stat Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (slots). /bin/dmesg | grep -i perf may provide additional information.

This is because the stat_handle_error() returns COUNTER_FATAL when the 'slots' is used as leader of events.

There are three options to fix the issue.

  1. Do not expose /sys/bus/event_source/devices/cpu/events/slots to userspace so that pmu_have_event(pmu->name, "slots") returns false.

  2. Run cpuid at perf userspace and avoid using 'slots' if it is not supported in cpuid.

  3. Do not fatal perf if the leader is failed. Do not create events for an evsel if its leader is already failed.

So I tried to manually specify the events, not specifying slots:

./perf stat -e cache-misses -d ls

 Performance counter stats for 'ls':

             20145      cache-misses
            555870      L1-dcache-loads
             25832      L1-dcache-load-misses     #    4.65% of all L1-dcache accesses
   <not supported>      LLC-loads
   <not supported>      LLC-load-misses

       0.000948558 seconds time elapsed

       0.001025000 seconds user
       0.000000000 seconds sys

So, perf is finally useable in my WSL. Hope this helps people with similar errors.

Upvotes: 1

Baiyan Huang
Baiyan Huang

Reputation: 6781

You could install some generic version of perf, rather than the WSL2 version, like:

sudo apt install linux-tools-5.4.0-126-generic linux-tools-common

And then when you run perf, it will error out, like:

$ perf
WARNING: perf not found for kernel 5.10.16.3-microsoft

  You may need to install the following packages for this specific kernel:
    linux-tools-5.10.16.3-microsoft-standard-WSL2
    linux-cloud-tools-5.10.16.3-microsoft-standard-WSL2

This is because script /usr/bin/perf always trying to get the perf binary from uname -r

$ grep uname `which perf`
full_version=`uname -r`

We could replace /usr/bin/perf with the actual perf :

mv /usr/bin/perf /usr/bin/perf.bk && ln -s /usr/lib/linux-tools/5.4.0-126-generic/perf /usr/bin/perf

and then:

$ perf stat ls 1>/dev/null

 Performance counter stats for 'ls':

              1.79 msec task-clock:u              #    0.827 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               112      page-faults:u             #    0.063 M/sec
   <not supported>      cycles:u
   <not supported>      instructions:u
   <not supported>      branches:u
   <not supported>      branch-misses:u

       0.002158900 seconds time elapsed

       0.002182000 seconds user
       0.000000000 seconds sys

I think it is expected the hardware/cache counters are not available on WSL2

Upvotes: 11

cwhakes
cwhakes

Reputation: 173

The accepted answer works. However, some features are missing.

In order to get useful and demangled information, I had to install the following libs and then run make again.

  • libbabeltrace-dev
  • libunwind-dev
  • libdw-dev
  • binutils-dev
  • libiberty-dev

I'm not sure if all of them are necessary. However, those are adequate for cargo-flamegraph (my usecase) to work.

Upvotes: 13

Gloit
Gloit

Reputation: 691

You can install linux-tools-generic.

apt install linux-tools-generic

Then run perf using the install path /usr/lib/linux-tools/<linux-version>-generic/perf.

Some tools, like flamegraph, will use environment variable PERF as the perf path.

PERF=/usr/lib/linux-tools/<linux-version>-generic/perf flamegraph -- my_program

Upvotes: 59

Jakob Ledermann
Jakob Ledermann

Reputation: 31

If you follow the accepted answer, make sure you read the complains the make command prints at the start, as it might be missing some headers and disables functionality.

For me it disabled tui, gtk and demangling to name a few features.

Upvotes: 3

Biswapriyo
Biswapriyo

Reputation: 4281

WARNING: perf not found for kernel 4.19.84-microsoft

Because WSL2 uses custom Linux kernel. Its source code can be found here microsoft/WSL2-Linux-Kernel. We have to compile perf tools from it.

Procedure

  • Install required build packages. If you are using Ubuntu in WSL2 this is the required command:
sudo apt install build-essential flex bison libssl-dev libelf-dev
  • Clone the WSL2 Linux kernel repository:
git clone --depth=1 https://github.com/microsoft/WSL2-Linux-Kernel.git
  • Go to perf folder and compile it:
cd WSL2-Linux-Kernel/tools/perf
make

perf executable file will be in that folder.

Upvotes: 98

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