Re: [GIT pull] printk updates for 4.15

From: Thomas Gleixner
Date: Fri Nov 17 2017 - 20:00:54 EST

On Fri, 17 Nov 2017, Linus Torvalds wrote:
> On Fri, Nov 17, 2017 at 4:26 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> >
> > Here you go. It survived suspend resume in a VM.
> That looks almost too small.
> If this were to allow us to basically unify BOOTTIME/MONOTONIC, that
> would be lovely.

I surely missed something. John should figure that out faster than me.

> Should we just try it, with the understanding that we'll quite
> possibly have to just revert?

You've seen the warning in the changelog :)

> Assuming this works, what would the "phase two" patch that actually
> unifies the two (as opposed to make them have the same value) look
> like?
> Is that just basically just removing the dozen or so "offst_boot"
> uses, or are there other possible simplifications?

Pretty much. We can't get rid of CLOCK_BOOTTIME and the handling of it,
though we can remove one hrtimer clock base by mapping boot time to
monotonic. That's about it.