vm_map_ram (9) - Linux Man Pages

vm_map_ram: map pages linearly into kernel virtual address (vmalloc space)

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

pages

an array of pointers to the pages to be mapped

count

number of pages

node

prefer to allocate data structures on this node

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 failure

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