Re: [v1 2/2] device-dax: "Hotremove" persistent memory that is used like normal RAM

[Pavel Tatashin]

> > +
> > +       /* Walk and offline every singe memory_block of the dax region. */
> > +       lock_device_hotplug();
> > +       rc = walk_memory_range(start_pfn, end_pfn, dev, offline_memblock_cb);
> > +       unlock_device_hotplug();
> > +       if (rc)
> > +               return rc;
>
> This potential early return is the reason why memory hotremove is not
> reliable vs the driver-core. If this walk fails to offline the memory
> it will still be online, but the driver-core has no consideration for
> device-unbind failing. The ubind will proceed while the memory stays
> pinned.

Hi Dan,

Thank you for looking at this.  Are you saying, that if drv.remove()
returns a failure it is simply ignored, and unbind proceeds?

Pasha