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

On 2020/11/15 2:54, Jakub Kicinski wrote:

On Thu, 12 Nov 2020 11:33:14 +0800 Huazhong Tan wrote:

quoted

Add a control private flag in ethtool for enable/disable
DIM feature.

Signed-off-by: Huazhong Tan <redacted>

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.

.