Re: [PATCH] Add Multiple TX/RX Queues Support for WWAN Network Device

Hi Xiayu, Sergey,

quoted

quoted

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As for the default queues number selection it seems better to
implement the RTNL .get_num_rx_queues callback in the WWAN core
and
call optional driver specific callback through it. Something like
this:

static unsigned int wwan_rtnl_get_num_tx_queues(struct nlattr
*tb[])
{
    const char *devname = nla_data(tb[IFLA_PARENT_DEV_NAME]);
    struct wwan_device *wwandev = wwan_dev_get_by_name(devname);

    return wwandev && wwandev->ops && wwandev->ops-

quoted

get_num_tx_queues

?
              wwandev->ops->get_num_tx_queues() : 1;
}

static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = {
    ...
    .get_num_tx_queues = wwan_rtnl_get_num_tx_queues,
};

This way the default queues number selection will be implemented
in a
less surprising way.

But to be able to implement this we need to modify the RTNL ops
.get_num_tx_queues/.get_num_rx_queues callback definitions to
make
them able to accept the RTM_NEWLINK message attributes. This is
not
difficult since the callbacks are implemented only by a few
virtual
devices, but can be assumed too intrusive to implement a one
feature
for a single subsystem.

I agree with this solution. The wwan core can forward
get_num_tx_queues to per wwan driver callbacks or simply rely on a
'default_tx_queues' field in ops struct. As said previously, you need
a user for this change in the same series.

Regards,
Loic