Re: [PATCH rdma-next v1 11/11] RDMA/mlx5: Add support to get MR resource in RAW format

[Jason Gunthorpe <jgg@ziepe.ca>]

On Sun, Jun 07, 2020 at 11:47:11AM +0300, Maor Gottlieb wrote:
> 
> On 6/2/2020 4:23 PM, Leon Romanovsky wrote:
> > On Tue, Jun 02, 2020 at 09:27:02AM -0300, Jason Gunthorpe wrote:
> > > On Tue, Jun 02, 2020 at 09:21:18AM +0300, Leon Romanovsky wrote:
> > > > On Mon, Jun 01, 2020 at 09:26:46AM -0300, Jason Gunthorpe wrote:
> > > > > On Sun, May 31, 2020 at 12:54:14PM +0300, Leon Romanovsky wrote:
> > > > > > On Fri, May 29, 2020 at 08:31:21PM -0300, Jason Gunthorpe wrote:
> > > > > > > On Wed, May 27, 2020 at 04:54:08PM +0300, Leon Romanovsky wrote:
> > > > > > > > From: Maor Gottlieb <maorg@mellanox.com>
> > > > > > > > 
> > > > > > > > Add support to get MR (mkey) resource dump in RAW format.
> > > > > > > > 
> > > > > > > > Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
> > > > > > > > Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> > > > > > > >   drivers/infiniband/hw/mlx5/restrack.c | 3 ++-
> > > > > > > >   1 file changed, 2 insertions(+), 1 deletion(-)
> > > > > > > > 
> > > > > > > > diff --git a/drivers/infiniband/hw/mlx5/restrack.c b/drivers/infiniband/hw/mlx5/restrack.c
> > > > > > > > index 9e1389b8dd9f..834886536127 100644
> > > > > > > > +++ b/drivers/infiniband/hw/mlx5/restrack.c
> > > > > > > > @@ -116,7 +116,8 @@ int mlx5_ib_fill_res_mr_entry(struct sk_buff *msg,
> > > > > > > >   	struct nlattr *table_attr;
> > > > > > > > 
> > > > > > > >   	if (raw)
> > > > > > > > -		return -EOPNOTSUPP;
> > > > > > > > +		return fill_res_raw(msg, mr->dev, MLX5_SGMT_TYPE_PRM_QUERY_MKEY,
> > > > > > > > +				    mlx5_mkey_to_idx(mr->mmkey.key));
> > > > > > > None of the raw functions actually share any code with the non raw
> > > > > > > part, why are the in the same function? In fact all the implemenations
> > > > > > > just call some other function for raw.
> > > > > > > 
> > > > > > > To me this looks like they should should all be a new op
> > > > > > > 'fill_raw_res_mr_entry' and drop the 'bool'
> > > > > > I don't think that this is right approach, we already created ops per-objects
> > > > > > o remove API multiplexing. Extra de-duplication will create too much ops
> > > > > > without any real benefit.
> > > > > If there is no code sharing then they should not be in the same
> > > > > function at all. More ops is not really a problem.
> > > > Logically they are the same, user asks to get object property, driver returns.
> > > I'm starting to think it is also a mistake to have the same netlink op
> > > and trigger it by an inbound attribute. Are there other examples of
> > > that in netlink? Feels wrong
> > I have no idea, don't see it in devlink.c
> 
> Jason, do you mean trigger the raw by inbound attribute? I don't see a
> reason why not do that. Netlink attributes used for input and
> output. 

What examples do you have where the input attribute completely changes
the output format?

Jason