Re: [PATCH 0/6] mm: make movable onlining suck less

[Reza Arbab]

On Wed, Apr 05, 2017 at 08:42:39AM +0200, Michal Hocko wrote:
> On Tue 04-04-17 16:43:39, Reza Arbab wrote:
> > Okay, getting further. With this I can again repeatedly add and 
> > remove, but now I'm seeing a weird variation of that earlier issue:
> >
> > 1. add_memory(), online_movable
> >   /sys/devices/system/node/nodeX/memoryY symlinks are created.
> >
> > 2. offline, remove_memory()
> >   The node is offlined, since all memory has been removed, so all of
> >   /sys/devices/system/node/nodeX is gone. This is normal.
> >
> > 3. add_memory(), online_movable
> >   The node is onlined, so /sys/devices/system/node/nodeX is recreated,
> >   and the memory is added, but just like earlier in this email thread,
> >   the memoryY links are not there.
>
> Could you add some printks to see why the sysfs creation failed please?

Ah, simple enough. It's this, right at the top of 
register_mem_sect_under_node():

	if (!node_online(nid))
		return 0;

That being the case, I really don't understand why your patches make any 
difference. Is node_set_online() being called later than before somehow?

--
Reza Arbab