Re: [PATCH net 2/2] vmxnet3: use correct flag to indicate LRO feature

From: David Miller
Date: Fri Mar 16 2018 - 10:54:17 EST


From: Ronak Doshi <doshir@xxxxxxxxxx>
Date: Tue, 13 Mar 2018 12:41:41 -0700

> '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.
>
> Reported-by: Rachel Lunnon <rachel_lunnon@xxxxxxxxxxxxx>
> Signed-off-by: Ronak Doshi <doshir@xxxxxxxxxx>
> Acked-by: Shrikrishna Khare <skhare@xxxxxxxxxx>

Please add an appropriate "Fixes: " tag for the commit which introduced
this problem. This helps with -stable submissions and bug fix triage.