We used to limit the max pending DMAs to prevent guest from pinning too many
pages. But this could be removed since:
- We have the sk_wmem_alloc check in both tun/macvtap to do the same work
- This max pending check were almost useless since it was one done when there's
no new buffers coming from guest. Guest can easily exceeds the limitation.
- We've already check upend_idx != done_idx and switch to non zerocopy then. So
even if all vq->heads were used, we can still does the packet transmission.
So remove this check completely.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/vhost/net.c | 13 -------------
1 files changed, 0 insertions(+), 13 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index a035a89..ed3f165 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -38,8 +38,6 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
* Using this limit prevents one virtqueue from starving others. */
#define VHOST_NET_WEIGHT 0x80000
-/* MAX number of TX used buffers for outstanding zerocopy */
-#define VHOST_MAX_PEND 128
#define VHOST_GOODCOPY_LEN 256
/*
@@ -372,17 +370,6 @@ static void handle_tx(struct vhost_net *net)
break;
/* Nothing new? Wait for eventfd to tell us they refilled. */
if (head == vq->num) {
- int num_pends;
-
- /* If more outstanding DMAs, queue the work.
- * Handle upend_idx wrap around
- */
- num_pends = likely(nvq->upend_idx >= nvq->done_idx) ?
- (nvq->upend_idx - nvq->done_idx) :
- (nvq->upend_idx + UIO_MAXIOV -
- nvq->done_idx);
- if (unlikely(num_pends > VHOST_MAX_PEND))
- break;
if (unlikely(vhost_enable_notify(&net->dev, vq))) {
vhost_disable_notify(&net->dev, vq);
continue;
--
1.7.1
--
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