Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
lguest: net block unneeded receive queue update notifications
Number of exits transmitting 10GB Guest->Host before:
network xmit 7858610 recv 118136
After:
network xmit 7750233 recv 1
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
+13
-1
Documentation/lguest/lguest.c
+13
-1
Documentation/lguest/lguest.c
···
933
/* FIXME: Actually want DRIVER_ACTIVE here. */
934
if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK)
935
warn("network: no dma buffer!");
936
/* We'll turn this back on if input buffers are registered. */
937
return false;
938
} else if (out_num)
···
972
add_device_fd(vq->dev->fd);
973
/* Tell waker to listen to it again */
974
write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd));
975
}
976
977
/* When the Guest tells us they updated the status field, we handle it. */
···
1438
1439
/* Network devices need a receive and a send queue, just like
1440
* console. */
1441
-
add_virtqueue(dev, VIRTQUEUE_NUM, enable_fd);
1442
add_virtqueue(dev, VIRTQUEUE_NUM, handle_net_output);
1443
1444
/* We need a socket to perform the magic network ioctls to bring up the
···
933
/* FIXME: Actually want DRIVER_ACTIVE here. */
934
if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK)
935
warn("network: no dma buffer!");
936
+
937
+
/* Now tell it we want to know if new things appear. */
938
+
dev->vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY;
939
+
wmb();
940
+
941
/* We'll turn this back on if input buffers are registered. */
942
return false;
943
} else if (out_num)
···
967
add_device_fd(vq->dev->fd);
968
/* Tell waker to listen to it again */
969
write(waker_fd, &vq->dev->fd, sizeof(vq->dev->fd));
970
+
}
971
+
972
+
static void net_enable_fd(int fd, struct virtqueue *vq)
973
+
{
974
+
/* We don't need to know again when Guest refills receive buffer. */
975
+
vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY;
976
+
enable_fd(fd, vq);
977
}
978
979
/* When the Guest tells us they updated the status field, we handle it. */
···
1426
1427
/* Network devices need a receive and a send queue, just like
1428
* console. */
1429
+
add_virtqueue(dev, VIRTQUEUE_NUM, net_enable_fd);
1430
add_virtqueue(dev, VIRTQUEUE_NUM, handle_net_output);
1431
1432
/* We need a socket to perform the magic network ioctls to bring up the