From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Wed, 8 Apr 2015 20:33:25 -0300
Subject: KVM: lapic: mark LAPIC timer handler as irqsafe
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: dd13d17c917d6530794687b5cb6cc17830a73a95
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
Since lapic timer handler only wakes up a simple waitqueue,
it can be executed from hardirq context.
Reduces average cyclictest latency by 3us.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
arch/x86/kvm/lapic.c | 1 +
1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2069,6 +2069,7 @@ int kvm_create_lapic(struct kvm_vcpu *vc
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
HRTIMER_MODE_ABS_PINNED);
apic->lapic_timer.timer.function = apic_timer_fn;
+ apic->lapic_timer.timer.irqsafe = 1;
/*
* APIC is created enabled. This will prevent kvm_lapic_set_base from