Messages in this thread | | | Date | Mon, 30 Oct 2023 17:04:22 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] x86/tsc: Have tsc=recalibrate override things |
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On Mon, Oct 30, 2023 at 05:00:50PM +0100, Peter Zijlstra wrote: > --- > arch/x86/kernel/tsc.c | 26 +++++++++++++------------- > 1 file changed, 13 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 15f97c0abc9d..ebca304ecea0 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -1430,14 +1430,13 @@ static void tsc_refine_calibration_work(struct work_struct *work) > hpet ? "HPET" : "PM_TIMER", > (unsigned long)freq / 1000, > (unsigned long)freq % 1000); > + } else { > > - return; > + /* Make sure we're within 1% */ > + if (abs(tsc_khz - freq) > tsc_khz/100) > + goto out; > } > > - /* Make sure we're within 1% */ > - if (abs(tsc_khz - freq) > tsc_khz/100) > - goto out; > - > tsc_khz = freq; > pr_info("Refined TSC clocksource calibration: %lu.%03lu MHz\n", > (unsigned long)tsc_khz / 1000, > @@ -1475,18 +1474,19 @@ static int __init init_tsc_clocksource(void) > if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3)) > clocksource_tsc.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; > > - /* > - * When TSC frequency is known (retrieved via MSR or CPUID), we skip > - * the refined calibration and directly register it as a clocksource. > - */ > if (boot_cpu_has(X86_FEATURE_TSC_KNOWN_FREQ)) { > if (boot_cpu_has(X86_FEATURE_ART)) > art_related_clocksource = &clocksource_tsc; > - clocksource_register_khz(&clocksource_tsc, tsc_khz); > - clocksource_unregister(&clocksource_tsc_early); > > - if (!tsc_force_recalibrate) > - return 0; > + /* > + * When TSC frequency is known (retrieved via MSR or CPUID), we > + * skip the refined calibration and directly register it as a > + * clocksource. > + */ > + if (!tsc_force_recalibrate) { > + clocksource_register_khz(&clocksource_tsc, tsc_khz); > + clocksource_unregister(&clocksource_tsc_early);
+ return 0;
Clearly I should step away from the keyboard now.
> + } > } > > schedule_delayed_work(&tsc_irqwork, 0); >
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