On Mon 19-06-23 13:04:42, Haifeng Xu wrote:
> mem_cgroup_init() request for allocations from each possible node, and
> it's used to be a problem because NODE_DATA is not allocated for offline
> node. Things have already changed since commit 09f49dca570a9 ("mm: handle
> uninitialized numa nodes gracefully"), so it's unnecessary to check for
> !node_online nodes here.
>
> How to test?
>
> qemu-system-x86_64 \
> -kernel vmlinux \
> -initrd full.rootfs.cpio.gz \
> -append "console=ttyS0,115200 root=/dev/ram0 nokaslr earlyprintk=serial oops=panic panic_on_warn" \
> -drive format=qcow2,file=vm_disk.qcow2,media=disk,if=ide \
> -enable-kvm \
> -cpu host \
> -m 8G,slots=2,maxmem=16G \
> -smp cores=4,threads=1,sockets=2 \
> -object memory-backend-ram,id=mem0,size=4G \
> -object memory-backend-ram,id=mem1,size=4G \
> -numa node,memdev=mem0,cpus=0-3,nodeid=0 \
> -numa node,memdev=mem1,cpus=4-7,nodeid=1 \
> -numa node,nodeid=2 \
> -net nic,model=virtio,macaddr=52:54:00:12:34:58 \
> -net user \
> -nographic \
> -rtc base=localtime \
> -gdb tcp::6000
>
> Guest state when booting:
>
> [ 0.048881] NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x00000000-0xbfffffff]
> [ 0.050489] NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0x00000000-0x13fffffff]
> [ 0.052173] NODE_DATA(0) allocated [mem 0x13fffc000-0x13fffffff]
> [ 0.053164] NODE_DATA(1) allocated [mem 0x23fffa000-0x23fffdfff]
> [ 0.054187] Zone ranges:
> [ 0.054587] DMA [mem 0x0000000000001000-0x0000000000ffffff]
> [ 0.055551] DMA32 [mem 0x0000000001000000-0x00000000ffffffff]
> [ 0.056515] Normal [mem 0x0000000100000000-0x000000023fffffff]
> [ 0.057484] Movable zone start for each node
> [ 0.058149] Early memory node ranges
> [ 0.058705] node 0: [mem 0x0000000000001000-0x000000000009efff]
> [ 0.059679] node 0: [mem 0x0000000000100000-0x00000000bffdffff]
> [ 0.060659] node 0: [mem 0x0000000100000000-0x000000013fffffff]
> [ 0.061649] node 1: [mem 0x0000000140000000-0x000000023fffffff]
> [ 0.062638] Initmem setup node 0 [mem 0x0000000000001000-0x000000013fffffff]
> [ 0.063745] Initmem setup node 1 [mem 0x0000000140000000-0x000000023fffffff]
> [ 0.064855] DMA zone: 158 reserved pages exceeds freesize 0
> [ 0.065746] Initializing node 2 as memoryless
> [ 0.066437] Initmem setup node 2 as memoryless
> [ 0.067132] DMA zone: 158 reserved pages exceeds freesize 0
> [ 0.068037] On node 0, zone DMA: 1 pages in unavailable ranges
> [ 0.068265] On node 0, zone DMA: 97 pages in unavailable ranges
> [ 0.124755] On node 0, zone Normal: 32 pages in unavailable ranges
>
> cat /sys/devices/system/node/online
> 0-1
> cat /sys/devices/system/node/possible
> 0-2
>
> Signed-off-by: Haifeng Xu <haifeng.xu@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks a lo!
> ---
> v2:
> - extend changelog by test steps
> ---
> mm/memcontrol.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 4b27e245a055..c73c5fb33f65 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -7421,8 +7421,7 @@ static int __init mem_cgroup_init(void)
> for_each_node(node) {
> struct mem_cgroup_tree_per_node *rtpn;
>
> - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
> - node_online(node) ? node : NUMA_NO_NODE);
> + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
>
> rtpn->rb_root = RB_ROOT;
> rtpn->rb_rightmost = NULL;
> --
> 2.25.1
--
Michal Hocko
SUSE Labs
