On Fri, 9 Aug 2019, Lendacky, Thomas wrote:
> On 8/9/19 7:54 AM, Thomas Gleixner wrote:
> > + local_irq_disable();
> > /*
> > * Setup the APIC counter to maximum. There is no way the lapic
> > * can underflow in the 100ms detection time frame
> > */
> > __setup_APIC_LVTT(0xffffffff, 0, 0);
> >
> > - /* Let the interrupts run */
> > - local_irq_enable();
> > + /*
> > + * Methods to terminate the calibration loop:
> > + * 1) Global clockevent if available (jiffies)
> > + * 2) TSC if available and frequency is known
> > + */
> > + jif_start = READ_ONCE(jiffies);
> > +
> > + if (tsc_khz) {
> > + tsc_start = rdtsc();
> > + tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
> > + }
> > +
> > + while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
> > + /*
> > + * Enable interrupts so the tick can fire, if a global
> > + * clockevent device is available
> > + */
> > + local_irq_enable();
>
> Just a nit, but you end up doing this at the bottom of the loop, so you
> could move this invocation to just before the loop and avoid doing two
> local_irq_enable() calls in succession after the first iteration.
Indeed. Lets see how the reports go. That change is a nobrainer.
Thanks,
tglx
