Re: [PATCH 3.16 47/47] KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed

Joe Perches
2019-11-01T15:40:38Z

On Fri, 2019-11-01 at 04:07 -0400, Sasha Levin wrote:
> On Thu, Oct 31, 2019 at 03:53:23PM -0700, Joe Perches wrote:
> > On Thu, 2019-10-31 at 22:14 +0000, Ben Hutchings wrote:
> > > On Fri, 2019-10-25 at 12:05 -0700, Joe Perches wrote:
> > > > On Fri, 2019-10-25 at 19:03 +0100, Ben Hutchings wrote:
> > > > > 3.16.76-rc1 review patch. If anyone has any objections, please let me know.
> > > >
> > > > This seems more like an enhancement than a bug fix.
> > > >
> > > > Is this really the type of patch that is appropriate
> > > > for stable?
> > >
> > > Apparently so:
> > >
> > > v4.14.135: eba797dbf352 KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> > > v4.19.61: ba27a25df6df KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> > > v4.4.187: 505c011f9f53 KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> > > v4.9.187: 3984eae04473 KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> > > v5.1.20: edadec197fbf KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> > > v5.2.3: 9f062aef7356 KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
> >
> > I think not, but hey, maybe you and Greg do.
> >
> > Porting enhancements, even trivial ones, imo is
> > not a great thing for stable branches.
> >
> > My perspective is that only bug fixes should be
> > applied to stable branches.
>
> Usability issues are just as bad as code bugs. Our human interface is at
> least as important as the functionality of our code.

Umm.

#define DEBUG is not set here.

Changing from printk_once to pr_debug_ratelimited completely
eliminates the output from non CONFIG_DYNAMIC_DEBUG configs,
and this output message is not enabled by default either.