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VM_MAP_RAM(9) | Memory Management in Linux | VM_MAP_RAM(9) |
NAME¶
vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)SYNOPSIS¶
void * vm_map_ram(struct page ** pages, unsigned int count, int node, pgprot_t prot);
ARGUMENTS¶
struct page ** pagesan array of pointers to the pages to be mapped
unsigned int count
number of pages
int node
prefer to allocate data structures on this node
pgprot_t prot
memory protection to use. PAGE_KERNEL for regular
RAM
DESCRIPTION¶
If you use this function for less than VMAP_MAX_ALLOC pages, it could be faster than vmap so it's good. But if you mix long-life and short-life objects with vm_map_ram, it could consume lots of address space through fragmentation (especially on a 32bit machine). You could see failures in the end. Please use this function for short-lived objects.RETURN¶
a pointer to the address that has been mapped, or NULL on failureCOPYRIGHT¶
July 2017 | Kernel Hackers Manual 4.11 |