e5a9336adb
When ip6gre is created using ioctl, its features, such as
scatter-gather, GSO and tx-checksumming will be turned off:
# ip -f inet6 tunnel add gre6 mode ip6gre remote fd00::1
# ethtool -k gre6 (truncated output)
tx-checksumming: off
scatter-gather: off
tcp-segmentation-offload: off
generic-segmentation-offload: off [requested on]
But when netlink is used, they will be enabled:
# ip link add gre6 type ip6gre remote fd00::1
# ethtool -k gre6 (truncated output)
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
generic-segmentation-offload: on
This results in a loss of performance when gre6 is created via ioctl.
The issue was found with LTP/gre tests.
Fix it by moving the setup of device features to a separate function
and invoke it with ndo_init callback because both netlink and ioctl
will eventually call it via register_netdevice():
register_netdevice()
- ndo_init() callback -> ip6gre_tunnel_init() or ip6gre_tap_init()
- ip6gre_tunnel_init_common()
- ip6gre_tnl_init_features()
The moved code also contains two minor style fixes:
* removed needless tab from GRE6_FEATURES on NETIF_F_HIGHDMA line.
* fixed the issue reported by checkpatch: "Unnecessary parentheses around
'nt->encap.type == TUNNEL_ENCAP_NONE'"
Fixes: ac4eb009e477 ("ip6gre: Add support for basic offloads offloads excluding GSO")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.