Documentation
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Overview ¶
Command refault-probe is a field diagnostic for the §9 page-cache pressure sensor (internal/engine/memory/pressure_os.go). It prints, once per second, the raw workingset_refault counter this process can see next to the sensor's sampled rate and active state — same process, same instant, so a moving counter with a flat sensor rate indicts the sensor, not the environment.
With --thrash <file> it also generates workingset refaults itself: the file is mmap'd and pages are touched in a random order, twice per sweep, so pages join the kernel's workingset before eviction — run it inside a memory-capped cgroup smaller than the file and the eviction/re-touch cycle registers as refaults (a sequential cat loop does not: streamed pages never activate).
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