Re: perf stat issue with 7.0.0rc3

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Fri, Mar 13, 2026 at 02:13:18PM +0100, Thomas Richter wrote:
> Ian, 
> 
> I just discovered a strange behavior on linux 7.0.0rc3.
> 
> I run these commands on my x86 virtual machine:
> 
> bash-5.3# uname -m
> x86_64
> bash-5.3# perf -v
> perf version 6.18.13-200.fc43.x86_64
> bash-5.3# perf stat -- true
> 
>  Performance counter stats for 'true':
> 
>          1.108.929      task-clock                       #    0,437 CPUs utilized             
>                  0      context-switches                 #    0,000 /sec                      
>                  0      cpu-migrations                   #    0,000 /sec                      
>                 55      page-faults                      #   49,597 K/sec                     
>    <not supported>      cycles                                                                
> 
>        0,002536439 seconds time elapsed
> 
>        0,001363000 seconds user
>        0,001393000 seconds sys
> 
> bash-5.3#
> 
> This is the epected output, however when I use the perf version 7.0.0rc3:
> 
> bash-5.3# ./perf -v
> perf version 7.0.rc3.g1f318b96cc84
> bash-5.3# ./perf stat -- true
> Error:
> No supported events found.
> trace.args_alignment

And this last line is even stranger, in my case I get something else,
also on x86_64:

root@number:~#  perf stat -- true
Error:
No supported events found.
addr2line.style
root@number:~#

On an ARM machine:

acme@raspberrypi:~/git/perf-tools $ perf stat -- true
Error:
No supported events found.

acme@raspberrypi:~/git/perf-tools $ uname -a
Linux raspberrypi 6.12.62+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.62-1+rpt1 (2025-12-18) aarch64 GNU/Linux
acme@raspberrypi:~/git/perf-tools $

I'll try to bisect this later, thanks for the report!

- Arnaldo

> bash-5.3# 
> 
> Same happens on my s390 systems (LPAR and z/VM).
> Is this a known already?
> I guess this is a perf tool issue, same result when you execute this on a 7.0.0rc3
> kernel.
> 
> Any ideas where to start debugging
> -- 
> Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
> --
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