Re: [PATCH V3 net-next 06/10] net: hns3: add ethtool priv-flag for DIM

[tanhuazhong]

On 2020/11/15 2:54, Jakub Kicinski wrote:
> On Thu, 12 Nov 2020 11:33:14 +0800 Huazhong Tan wrote:
> > Add a control private flag in ethtool for enable/disable
> > DIM feature.
> >
> > Signed-off-by: Huazhong Tan <tanhuazhong@xxxxxxxxxx>
>
> Please work on a common ethtool API for the configuration instead of
> using private flags.
>
> Private flags were overused because the old IOCTL-based ethtool was
> hard to extend, but we have a netlink API now.
>
> For example here you're making a choice between device and DIM
> implementation of IRQ coalescing. You can add a new netlink attribute
> to the ETHTOOL_MSG_COALESCE_GET/ETHTOOL_MSG_COALESCE_SET commands which
> controls the type of adaptive coalescing (if enabled).

The device's implementation of IRQ coalescing will be removed, if DIM 
works ok for a long time. So could this private flag for DIM be 
uptreamed as a transition scheme? And adding a new netlink attrtibute to 
controls the type of adaptive coalescing seems useless for other drivers.

> One question I don't think we have a strong answer for is how to handle
> this extension from ethtool_ops point of view. Should we add a new
> "extended" op which drivers may start implementing? Or separate the
> structure passed in to the ops from the one used as uAPI?
>
> Thoughts anyone?
>
>
> Huazhong Tan, since the DIM and EQ/CQ patches may require more
> infrastructure work feel free to repost the first 4 patches separately,
> I can apply those as is.

ok, thanks.

> .