no events detected

[Ted Cooper]

Hey folks,

I have just compiled PAPI (git head, commit 9b49a7caeda61c054c68af11936701462e58996f, Nov 12) on Linux 5.15.5-arch1-1.  /proc/sys/kernel/perf_event_paranoid is 1, and I can count cycles with perf stat -e cycles. Followed the instructions in INSTALL.txt, no errors during compilation, but when I run papi_avail I get

...
Of 108 possible events, 0 are available, of which 0 are derived.

No events detected!  Check papi_component_avail to find out why.

When I run papi_component_avail, I get this:

0 theod@tauceti:~/git/papi/src$ utils/papi_component_avail
Available components and hardware information.
--------------------------------------------------------------------------------
PAPI version             : 6.0.0.1
Operating system         : Linux 5.15.5-arch1-1
Vendor string and code   : GenuineIntel (1, 0x1)
Model string and code    : 11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz (140, 0x8c)
CPU revision             : 1.000000
CPUID                    : Family/Model/Stepping 6/140/1, 0x06/0x8c/0x01
CPU Max MHz              : 4800
CPU Min MHz              : 400
Total cores              : 8
SMT threads per core     : 2
Cores per socket         : 4
Sockets                  : 1
Cores per NUMA region    : 8
NUMA regions             : 1
Running in a VM          : no
Number Hardware Counters : 20
Max Multiplex Counters   : 384
Fast counter read (rdpmc): yes
--------------------------------------------------------------------------------

Compiled-in components:
Name:   perf_event              Linux perf_event CPU counters
Name:   perf_event_uncore       Linux perf_event CPU uncore and northbridge
   \-> Disabled: No uncore PMUs or events found

Active components:
Name:   perf_event              Linux perf_event CPU counters
                                Native: 157, Preset: 0, Counters: 20
                                PMUs supported: ix86arch, perf, perf_raw, icl


--------------------------------------------------------------------------------

Any idea why this isn't working?  Thanks for reading, folks!

[Vince Weaver]

On Sun, 5 Dec 2021, Ted Cooper wrote:

> I have just compiled PAPI (git head, commit 9b49a7caeda61c054c68af11936701462e58996f,
> Nov 12) on Linux 5.15.5-arch1-1. /proc/sys/kernel/perf_event_paranoid is
> 1, and I can count cycles with perf stat -e cycles. Followed the
> instructions in INSTALL.txt, no errors during compilation, but when I run
> papi_avail I get
>
> ...
> Of 108 possible events, 0 are available, of which 0 are derived.
>
> No events detected! Check papi_component_avail to find out why.

You appear to have a 6/140/1 processor which I think is a Tigerlake?

This is new enough that I don't think the papi_events.csv file has an
entry for pre-defined events for it yet.

Vince Weaver
vincent...@maine.edu

[Vince Weaver]

ideally we would like to add PAPI support for that processor, but it's a
multistep process. First support would have to be added to libpfm4 (I
don't think it's there yet from a quick glance), then the pre-defined
events would have to be set up in PAPI. The second step can be
semi-automated these days I think, but it depends on having access to
Tigerlake hardware and I'm not sure if any of the PAPI developers have
that yet.

Vince


On Fri, 10 Dec 2021, Ted Cooper wrote:

> Thanks, that makes sense!

[Vince Weaver]

On Fri, 10 Dec 2021, Ted Cooper wrote:

> The main machine I run experiments on is Broadwell, and PAPI works there.
> This just came up when I set up PAPI on my new Tigerlake daily driver, so
> that I could get my research code to build locally, and I ran the tests
> after building PAPI and discovered the issue that I posted about. My
> research isn't blocking on Tigerlake support for predefined events. Just
> to make sure I understand, though, the native events should be fine, right?

any native events it reports should be fine to use. However if libpfm4
tigerlake support isn't available then the native events you get might
just be the linux kernel pre-defined events (rather than the actual full
set of native events supported by the chip).

Vince

[Vince Weaver]

and just to follow up, I was mistakenly looking at an old checkout of the
PAPI tree. Current git does have libpfm4 support for Tigerlake so it
should have the full set of native events, so those should work.

It's just PAPI doesn't have support for ice-lake/tiger-lake in the
papi_events.csv file yet so no pre-defined events are available.

On Fri, 10 Dec 2021, Ted Cooper wrote:

> Gotcha. Thanks Vince!

[Ted Cooper]

Thanks, that makes sense!

On Fri, Dec 10, 2021 at 10:43 AM Vince Weaver <vincent...@maine.edu> wrote:

[Ted Cooper]

The main machine I run experiments on is Broadwell, and PAPI works there.  This just came up when I set up PAPI on my new Tigerlake daily driver, so that I could get my research code to build locally, and I ran the tests after building PAPI and discovered the issue that I posted about.  My research isn't blocking on Tigerlake support for predefined events.  Just to make sure I understand, though, the native events should be fine, right?

[Ted Cooper]

Gotcha.  Thanks Vince!

[Vince Weaver]

From what I can tell libpfm4 supports your processor fine. Try doing a
"papi_native_avail" and it will list all of the events libpfm4 knows
about. You should be able to use any of the events.

What's missing are the preset events, ones like PAPI_TOT_CYC. To get
these the papi_events.csv file has to be updated for Tigerlake.
Often if a new processor is the same as the last generation this is just a
simple one line change, otherwise you might have to manually go through
and update the event list. This can be especially tricky for things like
cache events.

I think the papi team at UTK have a tool that can automate validating
the predefined event lists for a new processor, but I'm not sure if they
have access to a Tigerlake machine to do this on.

It does appear your processor does not have support for the uncore
counters yet in libpfm4, but that's a separate issue.

Vince




On Fri, 18 Mar 2022, Shashidhara Ganjugunte wrote:

> Hi Folks,
>
> I have a similar problem and would really like to get it to work on the
> following machine.
> Please see the output of papi_component_avail below.
>
> I would like to get some advice on possible next steps:
>
> 1. How do I confirm that libpfm4/PAPI do not have support for this
> processor.
> Also, is there any examples on how to do add support .
> 2. From this conversation it seems that I could still use some native/raw
> events.
> If there are examples on how to do that, it will be helpful too.
>
> Please let me know.

>
> Available components and hardware information.
> --------------------------------------------------------------------------------
> PAPI version : 6.0.0.1

> Operating system : Linux 4.12.14-122.60-default

> Vendor string and code : GenuineIntel (1, 0x1)

> Model string and code : Intel(R) Xeon(R) Gold 6342 CPU @ 2.80GHz (106,
> 0x6a)
> CPU revision : 6.000000
> CPUID : Family/Model/Stepping 6/106/6, 0x06/0x6a/0x06
> CPU Max MHz : 2800
> CPU Min MHz : 2800
> Total cores : 24
> SMT threads per core : 1
> Cores per socket : 24
> Sockets : 1
> Cores per NUMA region : 24

> NUMA regions : 1
> Running in a VM : no
> Number Hardware Counters : 20
> Max Multiplex Counters : 384

> Fast counter read (rdpmc): no

> --------------------------------------------------------------------------------
>
> Compiled-in components:
> Name: perf_event Linux perf_event CPU counters
> Name: perf_event_uncore Linux perf_event CPU uncore and northbridge
> \-> Disabled: No uncore PMUs or events found
>
> Active components:
> Name: perf_event Linux perf_event CPU counters
> Native: 157, Preset: 0, Counters: 20
> PMUs supported: ix86arch, perf, perf_raw,

> icx
> Thanks,
> Shashi
>
> --------------------------------------------------------------------------------

[Shashidhara Ganjugunte]

Hi Vince,

Thank you very much for the quick response.

I will take a look at the native events and see if I can use them.

Best Regards,

Shashi

[Shashidhara Ganjugunte]

Hi Folks,

I am running into a similar issue. I am also not finding events from PAPI.

Please let me know if this is expected. Further, if I need to add support is there any good documentation that explains how to do it.

Please let me know.

Thanks,

Shashi

$ ./papi_component_avail

Available components and hardware information.
--------------------------------------------------------------------------------
PAPI version             : 6.0.0.1

Operating system         : Linux 4.12.14-122.60-default

Vendor string and code   : GenuineIntel (1, 0x1)

Model string and code    : Intel(R) Xeon(R) Gold 6342 CPU @ 2.80GHz (106, 0x6a)

CPU revision             : 6.000000
CPUID                    : Family/Model/Stepping 6/106/6, 0x06/0x6a/0x06
CPU Max MHz              : 2800
CPU Min MHz              : 2800
Total cores              : 24
SMT threads per core     : 1
Cores per socket         : 24

Sockets                  : 1
Cores per NUMA region    : 24

NUMA regions             : 1
Running in a VM          : no
Number Hardware Counters : 20
Max Multiplex Counters   : 384

Fast counter read (rdpmc): no

--------------------------------------------------------------------------------

Compiled-in components:
Name:   perf_event              Linux perf_event CPU counters
Name:   perf_event_uncore       Linux perf_event CPU uncore and northbridge
   \-> Disabled: No uncore PMUs or events found

Active components:
Name:   perf_event              Linux perf_event CPU counters
                                Native: 157, Preset: 0, Counters: 20

                                PMUs supported: ix86arch, perf, perf_raw, icx


--------------------------------------------------------------------------------

On Tuesday, December 14, 2021 at 1:29:01 PM UTC-8 Ted Cooper wrote:

[Shashidhara Ganjugunte]

Hi Folks,

I have a similar problem and would really like to get it to work on the following machine.

Please see the output of papi_component_avail below.

I would like to get some advice on possible next steps:

1. How do I confirm that libpfm4/PAPI do not have support for this processor.

    Also, is there any examples on how to do add support .

2. From this conversation it seems that I could still use some native/raw events.

     If there are examples on how to do that, it will be helpful too.

Please let me know.

Available components and hardware information.
--------------------------------------------------------------------------------
PAPI version             : 6.0.0.1

Operating system         : Linux 4.12.14-122.60-default

Vendor string and code   : GenuineIntel (1, 0x1)

Model string and code    : Intel(R) Xeon(R) Gold 6342 CPU @ 2.80GHz (106, 0x6a)
CPU revision             : 6.000000
CPUID                    : Family/Model/Stepping 6/106/6, 0x06/0x6a/0x06
CPU Max MHz              : 2800
CPU Min MHz              : 2800
Total cores              : 24
SMT threads per core     : 1
Cores per socket         : 24

Sockets                  : 1
Cores per NUMA region    : 24

NUMA regions             : 1
Running in a VM          : no
Number Hardware Counters : 20
Max Multiplex Counters   : 384

Fast counter read (rdpmc): no

--------------------------------------------------------------------------------

Compiled-in components:
Name:   perf_event              Linux perf_event CPU counters
Name:   perf_event_uncore       Linux perf_event CPU uncore and northbridge
   \-> Disabled: No uncore PMUs or events found

Active components:
Name:   perf_event              Linux perf_event CPU counters
                                Native: 157, Preset: 0, Counters: 20

                                PMUs supported: ix86arch, perf, perf_raw, icx
Thanks,

Shashi

--------------------------------------------------------------------------------

On Tuesday, December 14, 2021 at 1:29:01 PM UTC-8 Ted Cooper wrote: