From 351dc6477cd35136ce4668401b1b1332a62908a8 Mon Sep 17 00:00:00 2001 From: Andrey Smetanin Date: Fri, 16 Oct 2015 10:07:45 +0300 Subject: [PATCH] kvm/eventfd: avoid loop inside irqfd_update() The loop(for) inside irqfd_update() is unnecessary because any other value for irq_entry.type will just trigger schedule_work(&irqfd->inject) in irqfd_wakeup. Signed-off-by: Andrey Smetanin Reviewed-by: Roman Kagan Signed-off-by: Denis V. Lunev CC: Vitaly Kuznetsov CC: "K. Y. Srinivasan" CC: Gleb Natapov CC: Paolo Bonzini Signed-off-by: Paolo Bonzini --- virt/kvm/eventfd.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index b637965..518421e 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -238,20 +238,17 @@ static void irqfd_update(struct kvm *kvm, struct kvm_kernel_irqfd *irqfd) { struct kvm_kernel_irq_routing_entry *e; struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS]; - int i, n_entries; + int n_entries; n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi); write_seqcount_begin(&irqfd->irq_entry_sc); - irqfd->irq_entry.type = 0; - e = entries; - for (i = 0; i < n_entries; ++i, ++e) { - /* Only fast-path MSI. */ - if (e->type == KVM_IRQ_ROUTING_MSI) - irqfd->irq_entry = *e; - } + if (n_entries == 1) + irqfd->irq_entry = *e; + else + irqfd->irq_entry.type = 0; write_seqcount_end(&irqfd->irq_entry_sc); } -- 2.7.4