Re: [PATCH] mm/page_alloc: remove the static for local variable node_order

From: Andrew Morton
Date: Mon Jan 04 2021 - 18:24:55 EST


On Wed, 30 Dec 2020 12:42:33 +0000 Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:

> On Wed, Dec 30, 2020 at 07:40:14PM +0800, Hui Su wrote:
> > local variable node_order do not need the static here.
>
> It bloody well does. It can be up to 2^10 entries on x86 (and larger
> on others) That's 4kB which you've now moved onto the stack.

That being said, could we kmalloc the scratch area in
__build_all_zonelists()? And maybe remove that static spinlock?

(what blocks node and cpu hotplug in there??)