Re: [PATCH 0/2] timekeeping: cleanup _fast_ variety of functions
From: Thomas Gleixner
Date: Thu Jun 27 2019 - 18:21:08 EST
On Tue, 25 Jun 2019, Arnd Bergmann wrote:
> On Tue, Jun 25, 2019 at 10:19 AM Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
> >
> > When Arnd and I discussed this prior, he thought it best that I separate
> > these two commits out into a separate patchset, because they might
> > require additional discussion or consideration from you. They seem
> > straightforward enough to me, but if deliberations require me to make
> > some tweaks, I'm happy to do so.
>
> One concern I had was whether we want to replace 'fast' with something
> else, such as 'in_nmi' that might be less confusing. The current naming
> might be easy to confuse between 'fast' and 'coarse'.
>
> Another point might be whether we actually need more than one
> kind of accessor for each time domain, given how rarely these are
> used. In theory we could have the full set of combinations of fast:
> monotonic/real/boottime/raw (but not clocktai) with ktime_t/ns/seconds/ts64
> for 16 versions. We currently have four, and you are adding another
> four, but not the final eight. I'm not saying this is wrong, but
> it feels a bit arbitrary and could use an explanation why you feel that
> is the right subset.
>
> For coarse, we have ktime_t and ts64. The _seconds() accessors are
> coarse by definition, but we probably don't want to add _ns().
> We also don't have the combination of 'raw' with 'coarse' or 'seconds',
> as that seems to have no use case.
Can we please just add those which are actually needed. If new code misses
something we can add them anytime later.
Thanks,
tglx