Messages in this thread | | | Date | Fri, 14 Nov 2014 01:26:44 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH] timekeeping: Move persistent clock registration code from ARM to kernel |
| |
On Thu, 13 Nov 2014, John Stultz wrote: > On Thu, Nov 13, 2014 at 2:46 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > > Aside of that I really wonder why we need that persistent_clock stuff > > at all. We already have mechanisms to register persistent clocks AKA > > RTCs after the early boot process and update the wall clock time > > before we actually need it. Nothing in early boot depends on correct > > wall clock at all. > > > > So instead of adding more extra persistent clock nonsense, can we just > > move all of that to the place where it belongs, i.e. RTC? > > Sigh.. I've got this on an eventual todo list.. The big problem though > is that the RTC infrastructure can't be called with irqs off, so its > not as optimal for measuring suspend time. Some of the suspend-time > measurement with clocksources that don't halt is interesting here. > > So we need to add to the RTC infrastructure special accessors that are > safe when irqs are off, and we can then deprecate the persistent clock > bits. There's still evaluation quirks with setting the time earlier in > boot or not (possibly some rng effects as well there), but that could > be worked out if we had the suspend timing via safe RTC interfaces > sorted.
So we better work on this instead of creating more legacy enforcement APIs....
Thanks,
tglx
| |