From 6012ca8159a7f78e6fc5122a8e9f22d82e9723e9 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 12 Nov 2014 11:24:35 +0800 Subject: virtio-scsi: dataplane: suppress guest notification This patch uses vring_should_notify() to suppress guest notification, and looks notification frequency can be decreased from ~33K/sec to ~2K/sec in my test environment. Suggested-by: Stefan Hajnoczi Signed-off-by: Ming Lei Signed-off-by: Paolo Bonzini --- hw/scsi/virtio-scsi-dataplane.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'hw') diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index 969b931557..03a1e8cfcf 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -92,9 +92,14 @@ VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s, void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req) { + VirtIODevice *vdev = VIRTIO_DEVICE(req->vring->parent); + vring_push(&req->vring->vring, &req->elem, req->qsgl.size + req->resp_iov.size); - event_notifier_set(&req->vring->guest_notifier); + + if (vring_should_notify(vdev, &req->vring->vring)) { + event_notifier_set(&req->vring->guest_notifier); + } } static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier) -- cgit v1.2.3