diff options
author | Jason Wang <jasowang@redhat.com> | 2017-02-07 15:49:50 +0800 |
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committer | Michael S. Tsirkin <mst@redhat.com> | 2017-02-27 20:37:27 +0200 |
commit | e3b56cdd4351f0e227d4d847eeadff4c82aef1b9 (patch) | |
tree | 45d602addb89b2cd3cf1617ecb85275dad7d3f9e /drivers/virtio/virtio_pci_common.h | |
parent | 51be7a9a261ce18c520fb3928b168feb77522745 (diff) |
vhost: try avoiding avail index access when getting descriptor
If last avail idx is not equal to cached avail idx, we're sure there's
still available buffers in the virtqueue so there's no need to re-read
avail idx. So let's skip this to avoid unnecessary userspace memory
access and memory barrier. Pktgen test show about 3% improvement on rx
pps.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio/virtio_pci_common.h')
0 files changed, 0 insertions, 0 deletions