[Intel-wired-lan] [jkirsher/next-queue PATCH v2 2/7] net: Add support for subordinate device traffic classes

[Bowers, AndrewX]

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces at osuosl.org] On
> Behalf Of Alexander Duyck
> Sent: Tuesday, June 12, 2018 8:19 AM
> To: intel-wired-lan at osuosl.org; Kirsher, Jeffrey T
> <jeffrey.t.kirsher at intel.com>; netdev at vger.kernel.org
> Subject: [Intel-wired-lan] [jkirsher/next-queue PATCH v2 2/7] net: Add
> support for subordinate device traffic classes
> 
> This patch is meant to provide the basic tools needed to allow us to create
> subordinate device traffic classes. The general idea here is to allow
> subdividing the queues of a device into queue groups accessible through an
> upper device such as a macvlan.
> 
> The idea here is to enforce the idea that an upper device has to be a single
> queue device, ideally with IFF_NO_QUQUE set. With that being the case we
> can pretty much guarantee that the tc_to_txq mappings and XPS maps for
> the upper device are unused. As such we could reuse those in order to
> support subdividing the lower device and distributing those queues between
> the subordinate devices.
> 
> In order to distinguish between a regular set of traffic classes and if a device
> is carrying subordinate traffic classes I changed num_tc from a u8 to a s16
> value and use the negative values to represent the suboordinate pool
> values. So starting at -1 and running to -32768 we can encode those as pool
> values, and the existing values of 0 to 15 can be maintained.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck at intel.com>
> ---
>  include/linux/netdevice.h |   16 ++++++++
>  net/core/dev.c            |   89
> +++++++++++++++++++++++++++++++++++++++++++++
>  net/core/net-sysfs.c      |   21 ++++++++++-
>  3 files changed, 124 insertions(+), 2 deletions(-)

Tested-by: Andrew Bowers <andrewx.bowers at intel.com>