Mastering Linux Kernel Development

Zone modifiers

Following is a summarized list of modifiers used to specify the zone from which memory is to be sourced. Recall our discussions on zones in an earlier section; for each of them, a gfp flag is defined:

#define __GFP_DMA ((__force gfp_t)___GFP_DMA)#define __GFP_HIGHMEM ((__force gfp_t)___GFP_HIGHMEM)#define __GFP_DMA32 ((__force gfp_t)___GFP_DMA32)#define __GFP_MOVABLE ((__force gfp_t)___GFP_MOVABLE) /* ZONE_MOVABLE allowed */