Documentation/scheduler/sched-capacity.rst

127 2. Task utilization
135 while task utilization is specific to CFS, it is convenient to describe it here
138 Task utilization is a percentage meant to represent the throughput requirements
143 On an SMP system with fixed frequencies, 100% utilization suggests the task is a
144 busy loop. Conversely, 10% utilization hints it is a small periodic task that
173 The task utilization signal can be made frequency invariant using the following
179 task utilization of 25%.
184 CPU capacity has a similar effect on task utilization in that running an
211 The task utilization signal can be made CPU invariant using the following
218 invariant task utilization of 25%.
220 2.4 Invariant task utilization
223 Both frequency and CPU invariance need to be applied to task utilization in
225 utilization that is both CPU and frequency invariant is thus, for a given
232 In other words, invariant task utilization describes the behaviour of a task as
236 Any mention of task utilization in the following sections will imply its
239 2.5 Utilization estimation
242 Without a crystal ball, task behaviour (and thus task utilization) cannot
245 Tracking (PELT) mechanism, one of those yielding an *average* utilization (as
249 considering a "true" task utilization (using a crystal ball), the implementation
270 utilization. Architectures must define arch_scale_freq_capacity(cpu) for that
348 Furthermore, uclamp lets userspace specify a minimum and a maximum utilization
357 above. On top of that, uclamp is used to clamp the task utilization values,
363 By using uclamp, userspace can e.g. allow a busy loop (100% utilization) to run
365 periodic task (e.g. 10% utilization) to run on the highest-performance CPUs by
401   utilization estimation)