On Mon 04-01-21 15:23:57, Andrew Morton wrote: > 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? I am not sure we can (e.g. early init code) but even if we could, what would be an advantage. This code is called very seldom with a very shallow stacks so using the stack allocation sounds like the easiest thing to do. > (what blocks node and cpu hotplug in there??) Memory hotplug is excluded by the caller when it matters (e.g. no locking for the early init). -- Michal Hocko SUSE Labs
