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author | Michal Simek <[email protected]> | 2012-03-30 12:10:03 +0200 |
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committer | Michal Simek <[email protected]> | 2012-03-30 12:10:03 +0200 |
commit | 6a4770e335bd4df0a4577146f76e116ab6e23f40 (patch) | |
tree | 305056c20b6ccf3a4fed00e9e32f3a1dd039cd70 /tools/testing/selftests/vm/map_hugetlb.c | |
parent | ac64a9caa55bdfd8d24784f25c68cb7919ddabe3 (diff) | |
parent | f52b69f86e27903d6896ed5fa7cd280fec8de532 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into next
Diffstat (limited to 'tools/testing/selftests/vm/map_hugetlb.c')
-rw-r--r-- | tools/testing/selftests/vm/map_hugetlb.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/map_hugetlb.c b/tools/testing/selftests/vm/map_hugetlb.c new file mode 100644 index 000000000000..ac56639dd4a9 --- /dev/null +++ b/tools/testing/selftests/vm/map_hugetlb.c @@ -0,0 +1,79 @@ +/* + * 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 int 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); + return 1; + } + return 0; +} + +int main(void) +{ + void *addr; + int ret; + + 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); + ret = read_bytes(addr); + + munmap(addr, LENGTH); + + return ret; +} |