The arch_timing_* are not defined if timing functions are not
enabled, which results in compiler warnings about implicit
function declarations. So guard the header with its own
kconfig so the header can be unconditionally included by
other enough though timing functions are not enabled.
Note this is done inside the doxygen @defgroup or else
doc build would fail as timing_api group cannot be found.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
We should not be initializing/starting/stoping timing functions
multiple times. So this changes how the timing functions are
structured to allow only one initialization, only start when
stopped, and only stop when started.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Add timing functions and APIs. This is now used with some of the tests
we have for performance and metrics and will be used whereever timing
informations are needed, for example for tracing, profiling and other
operations where timing info is critical.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
