Re: [PATCH rdma-next v3 08/14] RDMA/cgroup: Disambiguate devices across net namespaces

["Michal Koutný" <mkoutny@suse.com>]

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Hello Jiri.

On Thu, Jul 16, 2026 at 03:23:09PM +0200, Jiri Pirko <jiri@resnulli.us> wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> RDMA device names are unique only within a network namespace, but an
> RDMA cgroup can account resources for devices from multiple namespaces.
> Duplicate names therefore make cgroup output ambiguous and can cause
> limit writes to select the wrong device.

From the cover letter:
| A device in one network namespace therefore cannot use a name already
| taken in another, even in exclusive netns mode (netns_mode=0) where
| the two are otherwise isolated. Net devices have no such restriction -
| their names only need to be unique within a network namespace.

If this is modelled after net devices, why not make the visibility netns
based?
I.e. only list (write to) devices of the caller's netns.

> 
> Use the system-wide RDMA device index to distinguish duplicate names
> while preserving the existing UAPI for unique names. Reject ambiguous
> name-only writes with -ENOTUNIQ and expose a complete device view to
> administrators.

I admit, the administrators won't get the full view but that's no
different from the netns devices situation.

Regards,
Michal

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