7bf481d7e7
Currently each packet inserted in eswitch is tagged with a internal
metadata to indicate source vport. Metadata tagging is not always
needed. Metadata insertion is needed for multi-port RoCE, failover
between representors and stacked devices. In many other cases,
metadata enablement is not needed.
Metadata insertion slows down the packet processing rate of the E-switch
when it is in switchdev mode.
Below table show performance gain with metadata disabled for VXLAN
offload rules in both SMFS and DMFS steering mode on ConnectX-5 device.
----------------------------------------------
| steering | metadata | pkt size | rx pps |
| mode | | | (million) |
----------------------------------------------
| smfs | disabled | 128Bytes | 42 |
----------------------------------------------
| smfs | enabled | 128Bytes | 36 |
----------------------------------------------
| dmfs | disabled | 128Bytes | 42 |
----------------------------------------------
| dmfs | enabled | 128Bytes | 36 |
----------------------------------------------
Hence, allow user to disable metadata using driver specific devlink
parameter. Metadata setting of the eswitch is applicable only for the
switchdev mode.
Example to show and disable metadata before changing eswitch mode:
$ devlink dev param show pci/0000:06:00.0 name esw_port_metadata
pci/0000:06:00.0:
name esw_port_metadata type driver-specific
values:
cmode runtime value true
$ devlink dev param set pci/0000:06:00.0 \
name esw_port_metadata value false cmode runtime
$ devlink dev eswitch set pci/0000:06:00.0 mode switchdev
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Vu Pham <vuhuong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
changelog:
v1->v2:
- added performance numbers in commit log
- updated commit log and documentation for switchdev mode
- added explicit note on when user can disable metadata in
documentation
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.