On Mon, Feb 08, 2021 at 07:07:35PM +0200, Ido Schimmel wrote:

On Mon, Feb 08, 2021 at 11:07:02AM +0200, Leon Romanovsky wrote:

quoted

On Mon, Feb 08, 2021 at 10:57:46AM +0200, Ido Schimmel wrote:

quoted

On Mon, Feb 08, 2021 at 09:03:50AM +0200, Leon Romanovsky wrote:

quoted

On Mon, Feb 01, 2021 at 08:08:37PM +0200, Ido Schimmel wrote:

quoted

On Mon, Feb 01, 2021 at 09:37:11AM +0800, Chris Mi wrote:

quoted

Hi Ido,

On 1/30/2021 10:42 PM, Ido Schimmel wrote:

quoted

On Fri, Jan 29, 2021 at 12:30:09PM -0800, Jakub Kicinski wrote:

quoted

On Fri, 29 Jan 2021 14:08:39 +0800 Chris Mi wrote:

quoted

Instead of discussing it several days, maybe it's better to review
current patch, so that we can move forward :)

It took you 4 revisions to post a patch which builds cleanly and now
you want to hasten the review? My favorite kind of submission.

The mlxsw core + spectrum drivers are 65 times the size of psample
on my system. Why is the dependency a problem?

mlxsw has been using psample for ~4 years and I don't remember seeing a
single complaint about the dependency. I don't understand why this patch
is needed.

Please see Saeed's comment in previous email:

"

The issue is with distros who ship modules independently.. having a
hard dependency will make it impossible for basic mlx5_core.ko users to
load the driver when psample is not installed/loaded.

I prefer to have 0 dependency on external modules in a HW driver.
"

I saw it, but it basically comes down to personal preferences.

It is more than personal preferences. In opposite to the mlxsw which is
used for netdev only, the mlx5_core is used by other subsystems, e.g. RDMA,
so Saeed's request to avoid extra dependencies makes sense.

We don't need psample dependency to run RDMA traffic.

Right, you don't need it. The dependency is "PSAMPLE || PSAMPLE=n". You
can compile out psample and RDMA will work.

So do you suggest to all our HPC users recompile their distribution kernel
just to make sure that psample is not called?

I don't know. What are they complaining about? That psample needs to be
installed for mlx5_core to be loaded? How come the rest of the
dependencies are installed?

The psample module was first dependency that caught our attention. It is
here as an example of such not-needed dependency. Like Saeed said, we are
interested in more general solution that will allow us to use external
modules in fully dynamic mode.

Internally, as a preparation to the submission of mlx5 code that used nf_conntrack,
we found that restart of firewald service will bring down our mlx5_core driver, because
of such dependency.

So to answer on your question, HPC didn't complain yet, but we don't have any plans
to wait till they complain.

Or are they complaining about the size / memory footprint of psample?
Because then they should first check mlx5_core when all of its options
are blindly enabled as part of a distribution config.

You are too focused on psample, while Saeed and I are saying more
general statement "I prefer to have 0 dependency on external modules in a HW driver."

This is another problem with mlx5 - complete madness with config options
that are not possible to test.
➜  kernel git:(rdma-next) grep -h "config MLX" drivers/net/ethernet/mellanox/mlx5/core/Kconfig | awk '{ print $2}' | sort |uniq |wc -l
19

And it is not weak dependency, but still hard dependency because you
need to recompile your kernel/module to disable/enable it. Any service
that will need to reload psample module for some reason will remove
mlx5_core.

Thanks