diff options
author | Dave Young <dyoung@redhat.com> | 2012-03-28 21:42:56 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-29 00:14:37 (GMT) |
commit | f0f57b2b1488251970c25deea0ea150a8d0911ed (patch) | |
tree | 6a1021691892c6bfa6c7471861b87eb72cd1be1a /Documentation/vm/hugepage-shm.c | |
parent | 63e315535abe0d820d0e3db4c06bc5de74aeefc8 (diff) | |
download | linux-fsl-qoriq-f0f57b2b1488251970c25deea0ea150a8d0911ed.tar.xz |
mm: move hugepage test examples to tools/testing/selftests/vm
hugepage-mmap.c, hugepage-shm.c and map_hugetlb.c in Documentation/vm are
simple pass/fail tests, It's better to promote them to
tools/testing/selftests.
Thanks suggestion of Andrew Morton about this. They all need firstly
setting up proper nr_hugepages and hugepage-mmap need to mount hugetlbfs.
So I add a shell script run_vmtests to do such work which will call the
three test programs and check the return value of them.
Changes to original code including below:
a. add run_vmtests script
b. return error when read_bytes mismatch with writed bytes.
c. coding style fixes: do not use assignment in if condition
[akpm@linux-foundation.org: build the targets before trying to execute them]
[akpm@linux-foundation.org: Documentation/vm/ no longer has a Makefile. Fixes "make clean"]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/vm/hugepage-shm.c')
-rw-r--r-- | Documentation/vm/hugepage-shm.c | 98 |
1 files changed, 0 insertions, 98 deletions
diff --git a/Documentation/vm/hugepage-shm.c b/Documentation/vm/hugepage-shm.c deleted file mode 100644 index 07956d8..0000000 --- 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; -} |