[Cc Andi] On Fri 03-07-20 11:10:01, Michal Suchanek wrote: > On Wed, Jul 01, 2020 at 02:21:10PM +0200, Michal Hocko wrote: > > On Wed 01-07-20 13:30:57, David Hildenbrand wrote: [...] > > > Yep, looks like it. > > > > > > [ 0.009726] SRAT: PXM 1 -> APIC 0x00 -> Node 0 > > > [ 0.009727] SRAT: PXM 1 -> APIC 0x01 -> Node 0 > > > [ 0.009727] SRAT: PXM 1 -> APIC 0x02 -> Node 0 > > > [ 0.009728] SRAT: PXM 1 -> APIC 0x03 -> Node 0 > > > [ 0.009731] ACPI: SRAT: Node 0 PXM 1 [mem 0x00000000-0x0009ffff] > > > [ 0.009732] ACPI: SRAT: Node 0 PXM 1 [mem 0x00100000-0xbfffffff] > > > [ 0.009733] ACPI: SRAT: Node 0 PXM 1 [mem 0x100000000-0x13fffffff] > > > > This begs a question whether ppc can do the same thing? > Or x86 stop doing it so that you can see on what node you are running? > > What's the point of this indirection other than another way of avoiding > empty node 0? Honestly, I do not have any idea. I've traced it down to Author: Andi Kleen <ak@xxxxxxx> Date: Tue Jan 11 15:35:48 2005 -0800 [PATCH] x86_64: Fix ACPI SRAT NUMA parsing Fix fallout from the recent nodemask_t changes. The node ids assigned in the SRAT parser were off by one. I added a new first_unset_node() function to nodemask.h to allocate IDs sanely. Signed-off-by: Andi Kleen <ak@xxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxx> which doesn't really tell all that much. The historical baggage and a long term behavior which is not really trivial to fix I suspect. -- Michal Hocko SUSE Labs