Re: [Y2038] [PATCH] drm/sti: Use 64-bit timestamps

From: Arnd Bergmann
Date: Mon Apr 18 2016 - 06:32:26 EST


On Monday 18 April 2016 12:02:35 Vincent ABRIOU wrote:
>
> getrawmonotonic comes from a legacy code so the use is not intentional.
> Honestly, it is not clear to me the difference between monotonic and
> rawmonotonic. But in the debug context in which it is used, ktime_get
> and ktime_get_raw will deliver the same level of information we need. So
> implementation done by Tina is fine for me.
>

Ok, cool, thanks for confirming!

FWIW, the best way I can see for illustrating the difference is that
rawmonotonic time is for things that should be synchronized with the
machines clock generators (e.g. A/V sync), while monotonic time is
for the case where you want to synchronize with another machine (or
the internet) that may have a slightly different clock generator but
uses NTP to correct for that.

In most cases the difference is irrelevant and we tend to use monotonic
time by default.

Arnd