On 2016-12-26 07:54:08 [+0100], Mike Galbraith wrote: Not so sure about it.
> --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1540,7 +1540,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu > kvm_vcpu_write_tsc_offset(vcpu, offset); > raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags); > > - spin_lock(&kvm->arch.pvclock_gtod_sync_lock); > + raw_spin_lock(&kvm->arch.pvclock_gtod_sync_lock); > if (!matched) { > kvm->arch.nr_vcpus_matched_tsc = 0; > } else if (!already_matched) { > @@ -1548,7 +1548,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu > } > > kvm_track_tsc_matching(vcpu); > - spin_unlock(&kvm->arch.pvclock_gtod_sync_lock); > + raw_spin_unlock(&kvm->arch.pvclock_gtod_sync_lock); > } > > EXPORT_SYMBOL_GPL(kvm_write_tsc); > @@ -1715,7 +1715,7 @@ static void kvm_gen_update_masterclock(s > struct kvm_vcpu *vcpu; > struct kvm_arch *ka = &kvm->arch; > > - spin_lock(&ka->pvclock_gtod_sync_lock); > + raw_spin_lock(&ka->pvclock_gtod_sync_lock); > kvm_make_mclock_inprogress_request(kvm); kvm_make_mclock_inprogress_request() will do zalloc_cpumask_var(). off-stack zalloc is not yet working but I would like to enable it. Also it does a SMP function call. Couldn't we go the other way around and drop the local_irq_disable()? Sebastian