Commit d2857b99 authored by Ronak Doshi's avatar Ronak Doshi Committed by Paolo Abeni
Browse files

vmxnet3: limit number of TXDs used for TSO packet 



Currently, vmxnet3 does not have a limit on number of descriptors
used for a TSO packet. However, with UPT, for hardware performance
reasons, this patch limits the number of transmit descriptors to 24
for a TSO packet.

Signed-off-by: default avatarRonak Doshi <doshir@vmware.com>
Acked-by: default avatarGuolin Yang <gyang@vmware.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent c7112ebd

drivers/net/vmxnet3/vmxnet3_defs.h

+2 −0
Original line number Diff line number Diff line
@@ -400,6 +400,8 @@ union Vmxnet3_GenericDesc { 


/* max # of tx descs for a non-tso pkt */

#define VMXNET3_MAX_TXD_PER_PKT 16

/* max # of tx descs for a tso pkt */

#define VMXNET3_MAX_TSO_TXD_PER_PKT 24



/* Max size of a single rx buffer */

#define VMXNET3_MAX_RX_BUF_SIZE  ((1 << 14) - 1)

drivers/net/vmxnet3/vmxnet3_drv.c

+17 −0
Original line number Diff line number Diff line
@@ -1061,6 +1061,23 @@ vmxnet3_tq_xmit(struct sk_buff *skb, struct vmxnet3_tx_queue *tq, 
			}

			tq->stats.copy_skb_header++;

		}

		if (unlikely(count > VMXNET3_MAX_TSO_TXD_PER_PKT)) {

			/* tso pkts must not use more than

			 * VMXNET3_MAX_TSO_TXD_PER_PKT entries

			 */

			if (skb_linearize(skb) != 0) {

				tq->stats.drop_too_many_frags++;

				goto drop_pkt;

			}

			tq->stats.linearized++;



			/* recalculate the # of descriptors to use */

			count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1;

			if (unlikely(count > VMXNET3_MAX_TSO_TXD_PER_PKT)) {

				tq->stats.drop_too_many_frags++;

				goto drop_pkt;

			}

		}

		if (skb->encapsulation) {

			vmxnet3_prepare_inner_tso(skb, &ctx);

		} else {