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Diffstat (limited to 'Documentation/vm/map_hugetlb.c')
-rw-r--r-- | Documentation/vm/map_hugetlb.c | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/Documentation/vm/map_hugetlb.c b/Documentation/vm/map_hugetlb.c deleted file mode 100644 index eda1a6d3578a..000000000000 --- a/Documentation/vm/map_hugetlb.c +++ /dev/null @@ -1,77 +0,0 @@ -/* - * Example of using hugepage memory in a user application using the mmap - * system call with MAP_HUGETLB flag. Before running this program make - * sure the administrator has allocated enough default sized huge pages - * to cover the 256 MB allocation. - * - * For ia64 architecture, Linux kernel reserves Region number 4 for hugepages. - * That means the addresses starting with 0x800000... will need to be - * specified. Specifying a fixed address is not required on ppc64, i386 - * or x86_64. - */ -#include <stdlib.h> -#include <stdio.h> -#include <unistd.h> -#include <sys/mman.h> -#include <fcntl.h> - -#define LENGTH (256UL*1024*1024) -#define PROTECTION (PROT_READ | PROT_WRITE) - -#ifndef MAP_HUGETLB -#define MAP_HUGETLB 0x40000 /* arch specific */ -#endif - -/* Only ia64 requires this */ -#ifdef __ia64__ -#define ADDR (void *)(0x8000000000000000UL) -#define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB | MAP_FIXED) -#else -#define ADDR (void *)(0x0UL) -#define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB) -#endif - -static void check_bytes(char *addr) -{ - printf("First hex is %x\n", *((unsigned int *)addr)); -} - -static void write_bytes(char *addr) -{ - unsigned long i; - - for (i = 0; i < LENGTH; i++) - *(addr + i) = (char)i; -} - -static void read_bytes(char *addr) -{ - unsigned long i; - - check_bytes(addr); - for (i = 0; i < LENGTH; i++) - if (*(addr + i) != (char)i) { - printf("Mismatch at %lu\n", i); - break; - } -} - -int main(void) -{ - void *addr; - - addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, 0, 0); - if (addr == MAP_FAILED) { - perror("mmap"); - exit(1); - } - - printf("Returned address is %p\n", addr); - check_bytes(addr); - write_bytes(addr); - read_bytes(addr); - - munmap(addr, LENGTH); - - return 0; -} |