lkml.org 
[lkml]   [2012]   [Sep]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] net: do not disable sg for AoE
From
Date
On Tue, 2012-09-18 at 20:20 -0400, Ed Cashin wrote:
> A change in a series of VLAN-related changes appears to have
> inadvertently disabled the use of the scatter gather feature of
> network cards for transmission of non-IP ethernet protocols like ATA
> over Ethernet (AoE). Below is a reference to the commit that
> introduces a "harmonize_features" function that turns off scatter
> gather when the NIC does not support hardware checksumming for the
> ethernet protocol of an sk buff.
>
> commit f01a5236bd4b140198fbcc550f085e8361fd73fa
> Author: Jesse Gross <jesse@nicira.com>
> Date: Sun Jan 9 06:23:31 2011 +0000
>
> net offloading: Generalize netif_get_vlan_features().
>
> The can_checksum_protocol function is not equipped to consider a
> protocol that does not require checksumming. Calling it for a
> protocol that requires no checksum is inappropriate.

Right, but...

[...]
> diff --git a/net/core/dev.c b/net/core/dev.c
> index d7fe32c..5531159 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2134,7 +2134,8 @@ static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
> static netdev_features_t harmonize_features(struct sk_buff *skb,
> __be16 protocol, netdev_features_t features)
> {
> - if (!can_checksum_protocol(features, protocol)) {
> + if (protocol != htons(ETH_P_AOE) &&

the generic way to check that would be skb->ip_summed != CHECKSUM_NONE.

Ben.

> + !can_checksum_protocol(features, protocol)) {
> features &= ~NETIF_F_ALL_CSUM;
> features &= ~NETIF_F_SG;
> } else if (illegal_highdma(skb->dev, skb)) {

--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.



\
 
 \ /
  Last update: 2012-09-19 22:41    [W:0.082 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site