Re: perf test failures in linux-next on s390

[Thomas Richter <tmricht@linux.ibm.com>]

On 6/14/23 16:57, Ian Rogers wrote:
> On Wed, Jun 14, 2023 at 1:32 AM Thomas Richter <tmricht@linux.ibm.com> wrote:

....

> 
> Smaller list is okay. Could you send me a zip of the sysfs
> (/sys/devices) ? At least one issue is that the code didn't find a
> core PMU. On non-hybrid x86 this would be /sys/devices/cpu, I think we
> spoke about this before for s390 and there are >1. The issue here is
> that the test found 0, and we're trying to use PMUs in the code now as
> a way to sort events. There's code/comment in util/pmu.c:
> 
> '''
> /**
>  * is_sysfs_pmu_core() - PMU CORE devices have different name other than cpu in
>  *         sysfs on some platforms like ARM or Intel hybrid. Looking for
>  *         possible the cpus file in sysfs files to identify whether this is a
>  *         core device.
>  * @name: The PMU name such as "cpu_atom".
>  */
> static int is_sysfs_pmu_core(const char *name)
> {
> char path[PATH_MAX];
> 
> if (!perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpus"))
> return 0;
> return file_available(path);
> }
> ...
> bool is_pmu_core(const char *name)
> {
> return !strcmp(name, "cpu") || is_sysfs_pmu_core(name);
> }
> '''
> 
> Thanks,
> Ian
> 

Maybe we should scan the directory

[linux-next]# ll /sys/bus/event_source/devices
total 0
lrwxrwxrwx 1 root root 0 Jun  2 15:11 cpum_cf -> ../../../devices/cpum_cf
lrwxrwxrwx 1 root root 0 Jun  2 15:11 cpum_cf_diag -> ../../../devices/cpum_cf_diag
lrwxrwxrwx 1 root root 0 Jun  2 15:11 cpum_sf -> ../../../devices/cpum_sf
lrwxrwxrwx 1 root root 0 Jun  2 15:11 kprobe -> ../../../devices/kprobe
lrwxrwxrwx 1 root root 0 Jun  2 15:11 software -> ../../../devices/software
lrwxrwxrwx 1 root root 0 Jun  2 15:11 tracepoint -> ../../../devices/tracepoint
lrwxrwxrwx 1 root root 0 Jun  2 15:11 uprobe -> ../../../devices/uprobe
[linux-next]#

This directory lists the PMUs available on s390, maybe this is true for
other platform...

Just me 2 cents
>> --
>> Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
>> --
>> Vorsitzender des Aufsichtsrats: Gregor Pillen
>> Geschäftsführung: David Faller
>> Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294
>>

-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
Vorsitzender des Aufsichtsrats: Gregor Pillen
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294