在 2022/8/17 21:57, Guo Zhi 写道:
Only add to used ring when a batch of buffer have all been used. And if
in order feature negotiated, only add the last used descriptor for a
batch of buffer.
Signed-off-by: Guo Zhi <qtxuning1999@xxxxxxxxxxx>
---
drivers/vhost/test.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index bc8e7fb1e635..57cdb3a3edf6 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -43,6 +43,9 @@ struct vhost_test {
static void handle_vq(struct vhost_test *n)
{
struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
+ struct vring_used_elem *heads = kmalloc(sizeof(*heads)
+ * vq->num, GFP_KERNEL);
Though it's a test device, it would be better to try avoid memory
allocation in the datapath.
And where is is freed?
Thanks
+ int batch_idx = 0;
unsigned out, in;
int head;
size_t len, total_len = 0;
@@ -84,11 +87,14 @@ static void handle_vq(struct vhost_test *n)
vq_err(vq, "Unexpected 0 len for TX\n");
break;
}
- vhost_add_used_and_signal(&n->dev, vq, head, 0);
+ heads[batch_idx].id = cpu_to_vhost32(vq, head);
+ heads[batch_idx++].len = cpu_to_vhost32(vq, len);
total_len += len;
if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))
break;
}
+ if (batch_idx)
+ vhost_add_used_and_signal_n(&n->dev, vq, heads, batch_idx);
mutex_unlock(&vq->mutex);
}
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