ACK: [SRU][N/P][PATCH 0/1] [UBUNTU 24.04] Kernel: Add CPUMF extended counter set for z17 (LP: #2114258)

[Stewart Hore]

On Sun, Jun 15, 2025 at 11:00:58AM +0200, Massimiliano Pellizzer wrote:
> BugLink: https://bugs.launchpad.net/bugs/2114258
>
> [ Impact ]
>
> s390/cpumf: Update CPU Measurement facility extended counter set support
>
> Update CPU Measurement counter facility support for the
> extended counter set for machine types 9175 and 9176.
>
> [ Fix ]
>
> Backport the following patch from upstream:
> - df194f57de71 s390/cpumf: Update CPU Measurement facility extended counter set
> support
>
> [ Test Plan ]
>
> Boot a z17 instance and run the command:
> ls -l /sys/devices/cpum_cf/events | wc -l
> The output must be 106.
>
> [ Where Problems Could Occur ]
>
> The fix modifies CPUMF event registration for IBM z17. A bug in this patch may
> cause incorrect event exposure on unsupported hardware, leading to invalid perf
> measurements, sysfs inconsistencies, or kernel warnings due to misconfigured or
> non-existent counters.

Acked-by: Stewart Hore <stewart.hore at canonical.com>

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