KVM: LAPIC: Retry tune per-vCPU timer_advance_ns if adaptive tuning goes insane (548f7fb2) · Commits · 戴 / test

arch/x86/kvm/lapic.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -71,6 +71,7 @@
		#define X2APIC_BROADCAST 0xFFFFFFFFul

		#define LAPIC_TIMER_ADVANCE_ADJUST_DONE 100
		#define LAPIC_TIMER_ADVANCE_ADJUST_INIT 1000
		/* step-by-step approximation to mitigate fluctuation */
		#define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8

		@@ -1546,8 +1547,8 @@ static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu,
		if (abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_DONE)
		apic->lapic_timer.timer_advance_adjust_done = true;
		if (unlikely(timer_advance_ns > 5000)) {
		timer_advance_ns = 0;
		apic->lapic_timer.timer_advance_adjust_done = true;
		timer_advance_ns = LAPIC_TIMER_ADVANCE_ADJUST_INIT;
		apic->lapic_timer.timer_advance_adjust_done = false;
		}
		apic->lapic_timer.timer_advance_ns = timer_advance_ns;
		}
		@@ -2344,7 +2345,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns)
		HRTIMER_MODE_ABS_PINNED);
		apic->lapic_timer.timer.function = apic_timer_fn;
		if (timer_advance_ns == -1) {
		apic->lapic_timer.timer_advance_ns = 1000;
		apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_ADJUST_INIT;
		apic->lapic_timer.timer_advance_adjust_done = false;
		} else {
		apic->lapic_timer.timer_advance_ns = timer_advance_ns;