mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 10:30:54 +07:00
f0f57b2b14
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>
101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
/*
|
|
* 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;
|
|
|
|
shmid = shmget(2, LENGTH, SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W);
|
|
if (shmid < 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);
|
|
exit(3);
|
|
}
|
|
dprintf("Done.\n");
|
|
|
|
if (shmdt((const void *)shmaddr) != 0) {
|
|
perror("Detach failure");
|
|
shmctl(shmid, IPC_RMID, NULL);
|
|
exit(4);
|
|
}
|
|
|
|
shmctl(shmid, IPC_RMID, NULL);
|
|
|
|
return 0;
|
|
}
|