Re: [RFC v2 5/5] eal: configure initial device probing

[Thomas Monjalon <thomas@monjalon.net>]

26/02/2026 17:50, Robin Jarry:
> David Marchand, Feb 26, 2026 at 17:20:
> > Some applications use port hotplug as their primary way for using DPDK
> > resources.
> > Having a systematic device probing is a problem when not all available
> > resources will be used by the application, as such applications won't set
> > an explicit allow list at startup.
> >
> > This is the case for OVS on systems with multiple mlx5 devices:
> > one device can be used by the kernel while the other(s) are used by DPDK.
> > In such a setup, the kernel used device may get reconfigured in
> > unexpected ways and trigger issues like the one described by Kevin
> > not so long ago in bugzilla 1873.
> >
> > Add an EAL option so that we can change the default behavior from
> > block-listing to allow-listing.
[...]
> > +	const char * const argv29[] = {prgname, prefix, mp_flag, eal_debug_logs,
> > +				       "--allow-explicitly" };
> 
> I am not convinced by the option name. What do you think of:
> 
> 	--no-autoprobe
> 
> That would match the Linux sriov_drivers_autoprobe sysfs.

The name --no-autoprobe is better indeed.

The exact effect of this option is to disable initial probing
of devices on all buses (except vdev).
Another name could be --no-initial-probing

I think we should add the opposite option as well
to allow changing the default mode later.
For such an option, --autoprobe looks better than --initial-probing.

Other opinions?


[...]
> Depending on what option name we settle on, could you add a short flag
> too? E.g.:
> 
> BOOL_ARG("--no-autoprobe", "-N", "Disable automatic probing of non-blocked devices", no_autoprobe)
> 
> Or:
> 
> BOOL_ARG("--no-autoprobe", "-P", "Disable automatic probing of non-blocked devices", no_autoprobe)

I don't see the benefit of a short flag.
It makes reading commands less obvious.