Re: [PATCH] of/platform: add initcall_debug logs for device creates

[Rob Herring]

On Mon, Jun 18, 2018 at 7:46 PM, Todd Poynor <toddpoynor@xxxxxxxxx> wrote:
> From: Todd Poynor <toddpoynor@xxxxxxxxxx>
>
> Add initcall_debug logs for the amount of time taken by each OF platform
> bus device create call.  For example:
>
>    of platform device create /reserved-memory/ramoops@a3800000 took
>    3255 usecs
>
> initcall_debug already reports the total of all such device creates
> as a single entry for function of_platform_default_populate_init (or
> similar, depending on the board).  The new logs help identify which of
> the potentially hundreds of device inits take significant amounts of
> time.

It's really the probe time that matters here. Outside of that,
creating the devices should be fairly constant time. So why not add
timing around non bus specific probe code (driver_probe_device)
instead of adding this in multiple places. Then you can remove the
timing from deferred probe code.

Rob