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linux-next/tools/testing/selftests/vm/map_hugetlb.c
Dave Young f0f57b2b14 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>
2012-03-28 17:14:37 -07:00

80 lines
1.7 KiB
C

/*
* 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;
}