diff options
Diffstat (limited to 'Documentation/vm')
| -rw-r--r-- | Documentation/vm/Makefile | 8 | ||||
| -rw-r--r-- | Documentation/vm/hugepage-mmap.c | 91 | ||||
| -rw-r--r-- | Documentation/vm/hugepage-shm.c | 98 | ||||
| -rw-r--r-- | Documentation/vm/map_hugetlb.c | 77 |
4 files changed, 0 insertions, 274 deletions
diff --git a/Documentation/vm/Makefile b/Documentation/vm/Makefile deleted file mode 100644 index e538864bfc63..000000000000 --- a/Documentation/vm/Makefile +++ /dev/null @@ -1,8 +0,0 @@ -# kbuild trick to avoid linker error. Can be omitted if a module is built. -obj- := dummy.o - -# List of programs to build -hostprogs-y := hugepage-mmap hugepage-shm map_hugetlb - -# Tell kbuild to always build the programs -always := $(hostprogs-y) diff --git a/Documentation/vm/hugepage-mmap.c b/Documentation/vm/hugepage-mmap.c deleted file mode 100644 index db0dd9a33d54..000000000000 --- a/Documentation/vm/hugepage-mmap.c +++ /dev/null @@ -1,91 +0,0 @@ -/* - * hugepage-mmap: - * - * Example of using huge page memory in a user application using the mmap - * system call. Before running this application, make sure that the - * administrator has mounted the hugetlbfs filesystem (on some directory - * like /mnt) using the command mount -t hugetlbfs nodev /mnt. In this - * example, the app is requesting memory of size 256MB that is backed by - * huge pages. - * - * For the ia64 architecture, the Linux kernel reserves Region number 4 for - * huge pages. That means that if one requires a fixed address, a huge page - * aligned address starting with 0x800000... will be required. If a fixed - * address is not required, the kernel will select an address in the proper - * range. - * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. - */ - -#include <stdlib.h> -#include <stdio.h> -#include <unistd.h> -#include <sys/mman.h> -#include <fcntl.h> - -#define FILE_NAME "/mnt/hugepagefile" -#define LENGTH (256UL*1024*1024) -#define PROTECTION (PROT_READ | PROT_WRITE) - -/* Only ia64 requires this */ -#ifdef __ia64__ -#define ADDR (void *)(0x8000000000000000UL) -#define FLAGS (MAP_SHARED | MAP_FIXED) -#else -#define ADDR (void *)(0x0UL) -#define FLAGS (MAP_SHARED) -#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; - int fd; - - fd = open(FILE_NAME, O_CREAT | O_RDWR, 0755); - if (fd < 0) { - perror("Open failed"); - exit(1); - } - - addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, fd, 0); - if (addr == MAP_FAILED) { - perror("mmap"); - unlink(FILE_NAME); - exit(1); - } - - printf("Returned address is %p\n", addr); - check_bytes(addr); - write_bytes(addr); - read_bytes(addr); - - munmap(addr, LENGTH); - close(fd); - unlink(FILE_NAME); - - return 0; -} diff --git a/Documentation/vm/hugepage-shm.c b/Documentation/vm/hugepage-shm.c deleted file mode 100644 index 07956d8592c9..000000000000 --- a/Documentation/vm/hugepage-shm.c +++ /dev/null @@ -1,98 +0,0 @@ -/* - * hugepage-shm: - * - * Example of using huge page memory in a user application using Sys V shared - * memory system calls. In this example the app is requesting 256MB of - * memory that is backed by huge pages. The application uses the flag - * SHM_HUGETLB in the shmget system call to inform the kernel that it is - * requesting huge pages. - * - * For the ia64 architecture, the Linux kernel reserves Region number 4 for - * huge pages. That means that if one requires a fixed address, a huge page - * aligned address starting with 0x800000... will be required. If a fixed - * address is not required, the kernel will select an address in the proper - * range. - * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. - * - * Note: The default shared memory limit is quite low on many kernels, - * you may need to increase it via: - * - * echo 268435456 > /proc/sys/kernel/shmmax - * - * This will increase the maximum size per shared memory segment to 256MB. - * The other limit that you will hit eventually is shmall which is the - * total amount of shared memory in pages. To set it to 16GB on a system - * with a 4kB pagesize do: - * - * echo 4194304 > /proc/sys/kernel/shmall - */ - -#include <stdlib.h> -#include <stdio.h> -#include <sys/types.h> -#include <sys/ipc.h> -#include <sys/shm.h> -#include <sys/mman.h> - -#ifndef SHM_HUGETLB -#define SHM_HUGETLB 04000 -#endif - -#define LENGTH (256UL*1024*1024) - -#define dprintf(x) printf(x) - -/* Only ia64 requires this */ -#ifdef __ia64__ -#define ADDR (void *)(0x8000000000000000UL) -#define SHMAT_FLAGS (SHM_RND) -#else -#define ADDR (void *)(0x0UL) -#define SHMAT_FLAGS (0) -#endif - -int main(void) -{ - int shmid; - unsigned long i; - char *shmaddr; - - if ((shmid = shmget(2, LENGTH, - SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) { - perror("shmget"); - exit(1); - } - printf("shmid: 0x%x\n", shmid); - - shmaddr = shmat(shmid, ADDR, SHMAT_FLAGS); - if (shmaddr == (char *)-1) { - perror("Shared memory attach failure"); - shmctl(shmid, IPC_RMID, NULL); - exit(2); - } - printf("shmaddr: %p\n", shmaddr); - - dprintf("Starting the writes:\n"); - for (i = 0; i < LENGTH; i++) { - shmaddr[i] = (char)(i); - if (!(i % (1024 * 1024))) - dprintf("."); - } - dprintf("\n"); - - dprintf("Starting the Check..."); - for (i = 0; i < LENGTH; i++) - if (shmaddr[i] != (char)i) - printf("\nIndex %lu mismatched\n", i); - dprintf("Done.\n"); - - if (shmdt((const void *)shmaddr) != 0) { - perror("Detach failure"); - shmctl(shmid, IPC_RMID, NULL); - exit(3); - } - - shmctl(shmid, IPC_RMID, NULL); - - return 0; -} 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; -} |