Change adds CPU stats module for tracing hooks. Module provides
information about percent of CPU usage based on tracing hooks
for threads switching in and out, interrupts enters and exits.
cpu_stats only distinguishes between idle thread, non idle
thread and scheduler.
Signed-off-by: Marek Pieta <Marek.Pieta@nordicsemi.no>
Any word started with underscore followed by and uppercase letter or a
second underscore is a reserved word according with C99.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Define generic interface and hooks for tracing to replace
kernel_event_logger and existing tracing facilities with something more
common.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
