The per-CPU vmstat worker is a problem on -RT workloads (because ideally the CPU is entirely reserved for the -RT app, without interference). The worker transfers accumulated per-CPU vmstat counters to global counters.
To resolve the problem, create two tunables: * Userspace configurable per-CPU vmstat threshold: by default the VM code calculates the size of the per-CPU vmstat arrays. This tunable allows userspace to configure the values. * Userspace configurable per-CPU vmstat worker: allow disabling the per-CPU vmstat worker. v2: - Improve documentation (Rik/Luiz). - Split patch in two (Luiz). - Fix comparison to include equal, in the helpers for stats accounting.
