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authorMing Lei <ming.lei@canonical.com>2014-11-12 11:24:35 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2014-11-12 11:19:19 +0100
commit6012ca8159a7f78e6fc5122a8e9f22d82e9723e9 (patch)
treeaf270b68589341666fab9dbd052a41d48b8a0cc3 /hw
parentc9cf45c1a475e594c560862d9df35b16e3a42702 (diff)
downloadqemu-6012ca8159a7f78e6fc5122a8e9f22d82e9723e9.zip
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 <stefanha@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/scsi/virtio-scsi-dataplane.c7
1 files changed, 6 insertions, 1 deletions
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)