On Tue, 2017-04-25 at 10:57 -0300, Marcelo Tosatti wrote: > 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. > > The patch below contains documentation which describes the tunables > in more detail.
The documentation says what the tunables do, but not how you should set them in different scenarios, or why. That could be a little more helpful to sysadmins.
