To even the latency, refill buffer right after being used.
Sign-off-by: Shirley Ma <xma@xxxxxxxxxx>
---
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0c7321c..c8201d4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -429,6 +429,22 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp)
return err;
}
+static bool fill_one(struct virtio_net *vi, gfp_t gfp)
+{
+ int err;
+
+ if (vi->mergeable_rx_bufs)
+ err = add_recvbuf_mergeable(vi, gfp);
+ else if (vi->big_packets)
+ err = add_recvbuf_big(vi, gfp);
+ else
+ err = add_recvbuf_small(vi, gfp);
+
+ if (err >= 0)
+ ++vi->num;
+ return err;
+}
+
/* Returns false if we couldn't fill entirely (OOM). */
static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
{
@@ -436,17 +452,10 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
bool oom;
do {
- if (vi->mergeable_rx_bufs)
- err = add_recvbuf_mergeable(vi, gfp);
- else if (vi->big_packets)
- err = add_recvbuf_big(vi, gfp);
- else
- err = add_recvbuf_small(vi, gfp);
-
+ err = fill_one(vi, gfp);
oom = err == -ENOMEM;
if (err < 0)
break;
- ++vi->num;
} while (err > 0);
if (unlikely(vi->num > vi->max))
vi->max = vi->num;
@@ -506,13 +515,13 @@ again:
receive_buf(vi->dev, buf, len);
--vi->num;
received++;
- }
-
- if (vi->num < vi->max / 2) {
- if (!try_fill_recv(vi, GFP_ATOMIC))
+ if (fill_one(vi, GFP_ATOMIC) < 0)
schedule_delayed_work(&vi->refill, 0);
}
+ /* notify buffers are refilled */
+ virtqueue_kick(vi->rvq);
+
/* Out of packets? */
if (received < budget) {
napi_complete(napi);
--
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