The Linux Kernel splits its memory space in Zones (eg, for x86_64):
DMA : @ 0 to 16MB, for legacy reasons
DMA32 : @ 16MB to 4GB, for 32bits hardware
Normal: @4GB to ..., the standard addressing.
```odin [00:13:12][0][~] cat /proc/pagetypeinfo
Page block order: 9
Pages per block: 512
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 0 0 0 0 2 1 1 0 1 0 0
Node 0, zone DMA, type Movable 0 0 0 0 0 0 0 0 0 1 3
Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Unmovable 1 0 0 0 0 0 1 1 1 1 0
Node 0, zone DMA32, type Movable 2 1 2 0 1 3 2 1 2 1 593
Node 0, zone DMA32, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Unmovable 870 530 391 157 103 41 9 2 1 0 0
Node 0, zone Normal, type Movable 5886 9235 5728 4072 1561 324 115 41 12 4 13018
Node 0, zone Normal, type Reclaimable 3 4 8 11 2 3 1 1 1 0 0
Node 0, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Isolate 0 0 0 0 0 0 0 0 0 0 0
A "clean" (ie non-fragmented) machine will have high order pages (8, 9, 10) :
while a more fragmented server will have mostly low-order pages:
```Page block order: 9
Pages per block: 512
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 0 1 1 0 2 1 1 0 1 0 0
Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Movable 0 0 0 0 0 0 0 0 0 1 3
Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Unmovable 159 6 2 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Reclaimable 9 8271 6716 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Movable 589 8078 3128 9 0 0 0 0 0 0 0
Node 0, zone DMA32, type Reserve 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Unmovable 1373 1465 1173 2 0 0 0 0 0 0 0
Node 0, zone Normal, type Reclaimable 14 5 13 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Movable 16256 80265 156907 529 67 0 0 0 0 0 0
Node 0, zone Normal, type Reserve 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type CMA 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Isolate 0 0 0 0 0 0 0 0 0 0 0
