Re: RDMA miniconf: Persistent device naming

[Bart Van Assche <Bart.VanAssche-Sjgp3cTcYWE@public.gmane.org>]

On Mon, 2017-07-31 at 14:36 +0300, Leon Romanovsky wrote:
> I would like to propose the discussion about ability to add
> persistent device naming to RDMA subsystem.
> 
> Right now, the devices receive their names by simple addition of new free
> index to the name (mlx5_0, mlx5_1 ...). Such naming scheme depends on the
> PCI probing and in case of device reset can rename device.
> 
> Such situation doesn't help to provide constant udev rules, reliable
> ibverbs hotplug and advanced "set command" of RDMAtool which at some
> point of time will require reinit of ib_device.
> 
> In this discussion, I want to present netdev implementation of such
> feature, talk about implications on libibverbs and suggest possible
> device name convention.

Hello Leon,

Does this mean that there is user space software that depends on these names?
Shouldn't all user space software be independent of the device names assigned
by the kernel? For e.g. SCSI disks this was solved a long time ago by making
/dev/disk/by-id/${name derived from persistent ID} soft links available. An
example:

$ ls -l /dev/disk/by-id/scsi-35001b44c698c2947
lrwxrwxrwx 1 root root 9 Jul 31 07:53 /dev/disk/by-id/scsi-35001b44c698c2947 -> ../../sda

Bart.--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html