scaphandre doesn't work on AMD Zen

[barnumbirr]

Bug description

Trrying to get scaphandre running on AMD Zen (Ryzen 5 Pro 2500U) results in thread panic.

To Reproduce

• Install msr-tools
• run scaphandre stdout -t 15

Output:

root@host:~# ./scaphandre stdout -t 15
thread 'main' panicked at 'Couldn't find intel_rapl modules.', src/sensors/powercap_rapl.rs:72:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Expected behavior

scaphandre should work as AMD RAPL support was added to kernel 5.8 and perf seems to return sensible data:

root@host:~# perf stat -a --per-socket -I 1000 -e power/energy-pkg/
#           time socket cpus             counts   unit events
     1.001342541 S0        1               2.06 Joules power/energy-pkg/
     2.002912211 S0        1               2.40 Joules power/energy-pkg/
     3.004453609 S0        1               1.87 Joules power/energy-pkg/
     3.837946645 S0        1               2.04 Joules power/energy-pkg/

Environment

• Debian Buster
• 5.9.15 (buster-backports)

Thank you again for creating scaphandre and please do let me know if I can help test this further.
Cheers.

[bpetit]

HI ! Thanks for reporting.

It seems we have to check for different modules if the cpu is from AMD.
I note here a post about some modules that might be the ones we have to check for: https://www.phoronix.com/scan.php?page=news_item&px=AMD-Energy-Driver-Working-Well

Investigations to come.

[kamaradclimber]

Same error with "AMD Ryzen 5 2600X Six-Core Processor" (perf also reports data).

Here is the full output with the correct option:

sudo docker run -v /sys/class/powercap:/sys/class/powercap -v /proc:/proc -e RUST_BACKTRACE=1 -ti hubblo/scaphandre stdout -t 1 
thread 'main' panicked at 'Couldn't find intel_rapl modules.', src/sensors/powercap_rapl.rs:72:13
stack backtrace:
   0: std::panicking::begin_panic
             at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:505
   1: <scaphandre::sensors::powercap_rapl::PowercapRAPLSensor as scaphandre::sensors::Sensor>::generate_topology
             at ./src/sensors/powercap_rapl.rs:72
   2: <scaphandre::sensors::powercap_rapl::PowercapRAPLSensor as scaphandre::sensors::Sensor>::get_topology
             at ./src/sensors/powercap_rapl.rs:112
   3: scaphandre::exporters::stdout::StdoutExporter::new
             at ./src/exporters/stdout.rs:51
   4: scaphandre::run
             at ./src/lib.rs:60
   5: scaphandre::main
             at ./src/main.rs:90
   6: core::ops::function::FnOnce::call_once
             at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/ops/function.rs:227
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[bpetit]

Hi,

Thanks for reporting ! I'll create a PR for that. If you could test it, once its there and before merging, it would be great !

[bpetit]

It seems possible that a 5.11 kernel could be required: https://www.phoronix.com/scan.php?page=news_item&px=AMD-Zen-PowerCap-RAPL-5.11

I don't see quite clearly the requirement right now for AMD. I'll create a PR that just avoids panicking if the intel modules are not found. This way you could tell me what happens next. (sorry I don't have an AMD box right now, so I place my hopes on you to make that topic go forward :D )

I saw that perf seems to work in 5.8 in your case @barnumbirr . Let's see how it goes with scaphandre with that PR.

[bpetit]

Could you build and try with this version: #65 ?

🙏🏽

Let's see what happens and start from there :)

[kamaradclimber]

Thanks a lot for investigating this :)

RUST_BACKTRACE=1 ./target/debug/scaphandre stdout

scaphandre::sensors::powercap_rapl: Couldn't find intel_rapl modules.
thread 'main' panicked at 'Trick: if you are running on a vm, do not forget to use --vm parameter invoking scaphandre at the command line', src/sensors/mod.rs:238:18
stack backtrace:
   0: rust_begin_unwind
             at /build/rust/src/rustc-1.49.0-src/library/std/src/panicking.rs:495:5
   1: core::panicking::panic_fmt
             at /build/rust/src/rustc-1.49.0-src/library/core/src/panicking.rs:92:14
   2: core::option::expect_failed
             at /build/rust/src/rustc-1.49.0-src/library/core/src/option.rs:1260:5
   3: core::option::Option<T>::expect
             at /build/rust/src/rustc-1.49.0-src/library/core/src/option.rs:349:21
   4: scaphandre::sensors::Topology::add_cpu_cores
             at ./src/sensors/mod.rs:234:26
   5: <scaphandre::sensors::powercap_rapl::PowercapRAPLSensor as scaphandre::sensors::Sensor>::generate_topology
             at ./src/sensors/powercap_rapl.rs:106:9
   6: <scaphandre::sensors::powercap_rapl::PowercapRAPLSensor as scaphandre::sensors::Sensor>::get_topology
             at ./src/sensors/powercap_rapl.rs:112:24
   7: scaphandre::exporters::stdout::StdoutExporter::new
             at ./src/exporters/stdout.rs:51:30
   8: scaphandre::run
             at ./src/lib.rs:60:28
   9: scaphandre::main
             at ./src/main.rs:91:5
  10: core::ops::function::FnOnce::call_once
             at /build/rust/src/rustc-1.49.0-src/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[bpetit]

I'm looking for a hosting or cloud provider to get an AMD zen testing machine, but I'm having a hard time finding an offer at a reasonable price. Do you know some ? Or do you have such a machine available for test on the Internet by any chance ?

[bpetit]

I may have found one thanks to @airclovis ! 👏🏽

https://www.skysilk.com/amd-epyc-servers/

EDIT; after all it seems they provide only VPSs, no bare metal

[barnumbirr]

You'd probably run into the same issue with Hetzner CPX instances, don't think they're bare metal. 😒
My machines are unfortunately not available on the Internet.

[kamaradclimber]

If you are interested in testing on "AMD Ryzen 5 2600X Six-Core Processor", contact me at grego_scaphandre@familleseux.net and I'll provide you an access to a bare-metal machine (not a professional server, it's just a regular PC acting like a server).

[bpetit]

I may give it a try and I'll send you an email, thanks !

However I'm looking for a cloud/hosting offer too in order to integrate tests on amd in PR checks.

[bpetit]

I'll start some tests thanks to @kamaradclimber generous offer (thank you ! 🥳 )
After that, I may have a look to those offers from hertzner that are the most affordable ones I found for dedicated machines with AMD Zen cpus so far.