Re: [RFC PATCH] x86, numa: always initialize all possible nodes

Michal Hocko
2019-01-25T10:40:23Z

On Thu 24-01-19 19:51:44, Mike Rapoport wrote:
> On Thu, Jan 24, 2019 at 03:17:27PM +0100, Michal Hocko wrote:
> > a friendly ping for this. Does anybody see any problem with this
> > approach?
>
> FWIW, it looks fine to me.
>
> It'd just be nice to have a few more words in the changelog about *how* the
> x86 init was reworked ;-)

Heh, I thought it was there but nope... It probably just existed in my
head. Sorry about that. What about the following paragraphs added?
"
The new code relies on the arch specific initialization to allocate all
possible NUMA nodes (including memory less) - numa_register_memblks in
this case. Generic code then initializes both zonelists (__build_all_zonelists)
and allocator internals (free_area_init_nodes) for all non-null pgdats
rather than online ones.

For the x86 specific part also do not make new node online in alloc_node_data
because this is too early to know that. numa_register_memblks knows that
a node has some memory so it can make the node online appropriately.
init_memory_less_node hack can be safely removed altogether now.
"

--
Michal Hocko
SUSE Labs