Re: [PATCH v2 4/5] mm: memory_hotplug: Add memory hotremove probe device

From: Michal Hocko
Date: Mon Dec 04 2017 - 07:34:10 EST


On Mon 04-12-17 11:51:29, Andrea Reale wrote:
> On Thu 30 Nov 2017, 15:49, Michal Hocko wrote:
> > On Thu 23-11-17 11:14:52, Andrea Reale wrote:
> > > Adding a "remove" sysfs handle that can be used to trigger
> > > memory hotremove manually, exactly simmetrically with
> > > what happens with the "probe" device for hot-add.
> > >
> > > This is usueful for architecture that do not rely on
> > > ACPI for memory hot-remove.
> >
> > As already said elsewhere, this really has to check the online status of
> > the range and fail some is still online.
> >
>
> This is actually still done in remove_memory() (patch 2/5) with
> walk_memory_range. We just return an error rather than BUGing().
>
> Or are you referring to something else?

But you are not returning that error to the caller, are you?

[...]
> > > + nid = memory_add_physaddr_to_nid(phys_addr);
> > > + ret = lock_device_hotplug_sysfs();
> > > + if (ret)
> > > + return ret;
> > > +
> > > + remove_memory(nid, phys_addr,
> > > + MIN_MEMORY_BLOCK_SIZE * sections_per_block);
> > > + unlock_device_hotplug();
> > > + return count;

--
Michal Hocko
SUSE Labs