Re: [PATCH] x86/umwait: Fix error handling in umwait_init()

From: Thomas Gleixner
Date: Sat Aug 10 2019 - 09:09:47 EST


On Sat, 10 Aug 2019, Thomas Gleixner wrote:
> On Fri, 9 Aug 2019, Fenghua Yu wrote:
> > +/*
> > + * The CPU hotplug callback sets the control MSR to the original control
> > + * value.
> > + */
> > +static int umwait_cpu_offline(unsigned int cpu)
> > +{
> > + /*
> > + * This code is protected by the CPU hotplug already and
> > + * orig_umwait_control_cached is never changed after it caches
> > + * the original control MSR value in umwait_init(). So there
> > + * is no race condition here.
> > + */
> > + wrmsr(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached, 0);
>
> Even my brain compiler emits an error here.

Didn't parse correctly due to not enough coffee and dirty glasses. Sorry
for the noise.

Thanks,

tglx