In 1.9.0, the Linux pressure collector "fails" if you don't have /proc/pressure/irq

[siebenmann]

In 1.9.0, the Linux pressure collector fails if your kernel is not recent enough to have /proc/pressure/irq, which was added only in Linux 6.1. Many currently supported Linux distribution kernels are older than this; for example, Ubuntu LTS 22.04's server kernel is based on 5.15 (and I'm sure there are older LTS kernels out there). Unless node_exporter wants to require a minimum 6.1 kernel for the pressure collector, it should still work if /proc/pressure/irq is missing.

[siebenmann]

Oops, I forgot to mention this in the report. I put "fails" into quotes because I believe that the currently observed effects are that the collector reports a failure status but does report the available metrics. However, if I'm correct, this is just an accident of the code structure because /proc/pressure/irq is read last and its failure to exist and the subsequent error doesn't invalidate the results so far. Changing either of those would change the results so that actual data was omitted.

[SuperQ]

Thanks, yes, this is a bug.

[SuperQ]

I think I see where this has gone wrong. It should be easy to fix.