[SRU,Xenial,2/3] vmxnet3: use correct flag to indicate LRO feature

Message ID f2241cfec7d1591a754e7d4de5c7e864ff569456.1525385778.git.joseph.salisbury@canonical.com
State New
Headers show
  • Fixes for LP:1768143
Related show

Commit Message

Joseph Salisbury June 1, 2018, 4:10 p.m.
From: Ronak Doshi <doshir@vmware.com>

BugLink: http://bugs.launchpad.net/bugs/1768143

'Commit 45dac1d6ea04 ("vmxnet3: Changes for vmxnet3 adapter version 2
(fwd)")' introduced a flag "lro" in structure vmxnet3_adapter which is
used to indicate whether LRO is enabled or not. However, the patch
did not set the flag and hence it was never exercised.

So, when LRO is enabled, it resulted in poor TCP performance due to
delayed acks. This issue is seen with packets which are larger than
the mss getting a delayed ack rather than an immediate ack, thus
resulting in high latency.

This patch removes the lro flag and directly uses device features
against NETIF_F_LRO to check if lro is enabled.

Fixes: 45dac1d6ea04 ("vmxnet3: Changes for vmxnet3 adapter version 2 (fwd)")
Reported-by: Rachel Lunnon <rachel_lunnon@stormagic.com>
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 034f405793897a3c8f642935f5494b86c340cde7)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
 drivers/net/vmxnet3/vmxnet3_drv.c | 3 ++-
 drivers/net/vmxnet3/vmxnet3_int.h | 5 ++---
 2 files changed, 4 insertions(+), 4 deletions(-)


diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 9e1349d..168b706 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -1424,7 +1424,8 @@  vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq,
 			vmxnet3_rx_csum(adapter, skb,
 					(union Vmxnet3_GenericDesc *)rcd);
 			skb->protocol = eth_type_trans(skb, adapter->netdev);
-			if (!rcd->tcp || !adapter->lro)
+			if (!rcd->tcp ||
+			    !(adapter->netdev->features & NETIF_F_LRO))
 				goto not_lro;
 			if (segCnt != 0 && mss != 0) {
diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h
index 7a8c771..9b1194c 100644
--- a/drivers/net/vmxnet3/vmxnet3_int.h
+++ b/drivers/net/vmxnet3/vmxnet3_int.h
@@ -69,10 +69,10 @@ 
  * Version numbers
 /* a 32-bit int, each byte encode a verion number in VMXNET3_DRIVER_VERSION */
-#define VMXNET3_DRIVER_VERSION_NUM      0x01040c00
+#define VMXNET3_DRIVER_VERSION_NUM      0x01040d00
 #if defined(CONFIG_PCI_MSI)
 	/* RSS only makes sense if MSI-X is supported. */
@@ -331,7 +331,6 @@  struct vmxnet3_adapter {
 	u8                              version;
 	bool				rxcsum;
-	bool				lro;
 #ifdef VMXNET3_RSS
 	struct UPT1_RSSConf		*rss_conf;