On Wed, Oct 16, 2019 at 07:43:09PM +0200, Eugeniu Rosca wrote:
On Wed, Oct 16, 2019 at 07:26:44PM +0200, Marek Vasut wrote:
On 10/16/19 7:11 PM, Eugeniu Rosca wrote:
On Tue, Oct 15, 2019 at 10:43:41PM +0200, Marek Vasut wrote:
Add get_timer_us(), which is useful e.g. when we need higher precision timestamps.
FWIW, I agree with Simon that bootstage [1] can be an awesome tool for profiling and boot time measurements. With a bit of instrumentation and host-side scripting, it allows to produce accurate bootcharts like [2].
[1] https://patchwork.ozlabs.org/patch/1177393/#2281091 [2] https://i.ibb.co/mG6Xc1p/2019-10-16-190251.png
I don't need that though, I really only need to know how long the code spent between two points in code.
It can be accomplished in N ways. A quick and dirty way to use "bootstage" would be to add below instrumentation:
----------8<---------- bootstage_mark_name(BOOTSTAGE_ID_ALLOC, "count/time from here"); /*
- my-precious-code
*/ bootstage_mark_name(BOOTSTAGE_ID_ALLOC, "duration of my-precious-code"); ----------8<----------
It's likely orthogonal to what's being proposed in your patch.
Bottom line is "bootstage" already makes use of timer_get_boot_us(), so it's not entirely clear to me why another us-resolution timer API would be needed.