Re: [patch-rt] kvm: Convert pvclock_gtod_sync_lock to raw_spinlock_t
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2017-01-20 16:44:27
Also in:
lkml
On 2016-12-26 07:54:08 [+0100], Mike Galbraith wrote: Not so sure about it.
quoted hunk ↗ jump to hunk
--- 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