txt: ## usage.md
  class Telemetry::Instrument::Usage
  
  Instrument for collecting getrusage data
  
  ```raku
  class Telemetry::Instrument::Usage { }
  ```
  
  **Note:**  This class is a Rakudo-specific feature and not standard Raku.
  
  Objects of this class are generally not created by themselves, but rather through making a [snap](/type/Telemetry)shot.
  
  ## [Useful readings](#class_Telemetry::Instrument::Usage "go to top of document")[§](#Useful_readings "direct link")
  
  This class provides the following generally usable readings (in alphabetical order):
  
  * cpu
  
  The total amount of CPU time (in microseconds), essentially the sum of `cpu-user` and `cpu-sys`.
  
  * cpu-sys
  
  The number of microseconds of CPU used by the system.
  
  * cpu-user
  
  The number of microseconds of CPU used by the user program.
  
  * cpus
  
  The number of CPU's active, essentially `cpu` divided by `wallclock`.
  
  * max-rss
  
  The maximum resident set size (in KiB).
  
  * util%
  
  Percentage of CPU utilization, essentially 100 \* `cpus` / number of CPU cores.
  
  * wallclock
  
  The time the program has been executing (in microseconds).
  
  ## [Less useful readings](#class_Telemetry::Instrument::Usage "go to top of document")[§](#Less_useful_readings "direct link")
  
  The following readings may or may not contain sensible information, mostly depending on hardware and OS being used. Please check your local `getrusage` documentation for their exact meaning:
  
  ｢text｣ without highlighting
  
  ```
  
  
  ```
  
  name        getrusage struct name
  ====        =====================
  max-rss     ru_maxrss
  ix-rss      ru_ixress
  id-rss      ru_idrss
  is-rss      ru_isrss
  minf        ru_minflt
  majf        ru_majflt
  nswp        ru_nswap
  inb         ru_inblock
  outb        ru_oublock
  msnd        ru_msgsnd
  mrcv        ru_msgrcv
  nsig        ru_nsignals
  volcsw      ru_nvcsw
  invcsw      ru_nivcsw
  
  
  ```
  
  
  ```
  