Re: [tip:timers/urgent] ktime: Get rid of the union

From: Thomas Gleixner
Date: Wed Jan 04 2017 - 03:57:47 EST


On Tue, 3 Jan 2017, Peter Zijlstra wrote:

> On Sun, Dec 25, 2016 at 05:26:33AM -0800, tip-bot for Thomas Gleixner wrote:
> > Commit-ID: 64dac5c9e0f5a933e4520f0cb689b7b143925207
> > Gitweb: http://git.kernel.org/tip/64dac5c9e0f5a933e4520f0cb689b7b143925207
> > Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > AuthorDate: Sun, 25 Dec 2016 11:38:40 +0100
> > Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > CommitDate: Sun, 25 Dec 2016 13:11:50 +0100
> >
> > ktime: Get rid of the union
> >
> > ktime is a union because the initial implementation stored the time in
> > scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
> > variant for 32bit machines. The Y2038 cleanup removed the timespec variant
> > and switched everything to scalar nanoseconds. The union remained, but
> > become completely pointless.
> >
> > Get rid of the union and just keep ktime_t as simple typedef of type s64.
>
> All good stuff. One question that remains is why keep the type while
> removing the cycles_t type?

That would have been a massive surgery which I was not able to pull off on
top of the other changes.

Thanks,

tglx