Pipeline stall metrics break after a few seconds

[vient]

Built latest source, after 1-5 seconds pcm starts showing

Observed with w7-2595X CPU on Linux kernel 5.15

First noticed on pcm 202502 version from Ubuntu 25.10, this version is more stable but breaks the same way when I manipulate CPU frequency by changing AVX offsets forth and back.

Edit: version 202502 breaks exactly the same, seems that it works only until frequency changes. I tested first under load so frequency was pretty stable, and the only change was induced by my tweaking of AVX offsets. Without load it breaks pretty fast if CPU frequency is not fixed.

[JacksonBichard]

I found a likely root cause in pcm/src/cpucounters.h: Some TMA metric helpers appear to divide by getAllSlots(before, after) without a zero check. I’m tracing the affected functions now and working on a fix. I’ll also try to reproduce and test it locally.