Re: [RFC PATCH 06/13] m68k: Drop ARCH_USES_GETTIMEOFFSET

[Michael Schmitz]

Hi Finn,

Am 13.11.2018 um 16:14 schrieb Finn Thain:
> On Tue, 13 Nov 2018, Michael Schmitz wrote:
>
> > Hi Finn,
> >
> > Am 12.11.2018 um 22:06 schrieb Finn Thain:
> > > On Mon, 12 Nov 2018, Geert Uytterhoeven wrote:
> > >
> > > > Hi Finn,
> > > >
> > > > Thanks for your patch!
> > > >
> > > > On Mon, Nov 12, 2018 at 5:46 AM Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
> > > > wrote:
> > > > > The functions that implement arch_gettimeoffset are re-used by
> > > > > new clocksource drivers in subsequent patches.
> > > >
> > > > Disabling this first affects functionality during bisection, right?
> > >
> > > It means that all platforms have to use the 'jiffies' clocksource.
> >
> > So all that happens is timer granularity drops to 10ms, then gets restored by
> > the later patches?
>
> Yes, that was the plan, but I can't confirm that it worked out as I don't
> have any physical 68k hardware in front of me right now. If you can
> confirm this on your Atari Falcon, that would be great.

Will do.

> (It appears that a QEMU-emulated Mac does not benefit from having a
> clocksource that's more accurate than the 'jiffies' clocksource, in spite
> of "clocksource: Switched to clocksource via1".)

With the current code, kernel log timestamps have 10 ms resolution on 
Atari. Time resolution of times reported by initcall_debug is roughly 40 
us. I'd expect that changes with falling back to jiffies only. Might be 
worth a try on QEMU Mac.

Cheers,

	Michael

> The latest patches can be found at
> https://github.com/fthain/linux/commits/mac68k-queue/