Re: [PATCH 4.5 007/238] KVM: i8254: change PIT discard tick policy

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Apr 12, 2016 at 03:30:23PM +0200, Radim Krčmář wrote:
> 2016-04-11 18:21-0700, Greg Kroah-Hartman:
> > On Tue, Apr 12, 2016 at 12:23:35AM +0100, Ben Hutchings wrote:
> > > On Wed, 2016-03-02 at 22:56 +0100, Radim Krčmář wrote:
> >> > Even though there is a chance of regressions, I think we can fix the
> >> > LVT0 NMI bug without introducing a new tick policy.
> >> [...]
> >> 
> >> Given the 'chance of regressions', should we let this sit in mainline
> >> longer before including it in stable updates?
> > 
> > Hm, good point, Radim, what do you think, is this good to go to stable
> > now?  This has been in since 4.6-rc1, so it's been a few weeks with
> > people running it already...
> 
> I think it is good to go.  No reasonable workload should regress and the
> fixed use-case is common on old linux guest.
> 
> This patch makes a difference if the guest doesn't EOI in PIT interrupts
> before the next one arrives.  PIT would have been unreliable in that
> situation, so all worloads that that could regress have likely been
> avoided.  Changes to NMI injection would need even crazier guest to
> regress.

Ok, thanks, leaving it in.

greg k-h