| Date | Fri, 26 Jul 2019 20:30:55 +0200 | From | Thomas Gleixner <> | Subject | [patch 07/12] KVM: LAPIC: Mark hrtimer to expire in hard interrupt context |
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
On PREEMPT_RT enabled kernels unmarked hrtimers are moved into soft interrupt expiry mode by default.
While that's not a functional requirement for the KVM local APIC timer emulation, it's a latency issue which can be avoided by marking the timer so hard interrupt context expiry is enforced.
No functional change.
[ tglx: Split out from larger combo patch. Add changelog. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2302,7 +2302,7 @@ int kvm_create_lapic(struct kvm_vcpu *vc apic->vcpu = vcpu; hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, - HRTIMER_MODE_ABS); + HRTIMER_MODE_ABS_HARD); apic->lapic_timer.timer.function = apic_timer_fn; if (timer_advance_ns == -1) { apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_ADJUST_INIT;
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