add header file giving utility functions for hugepage

Add routines allocating/freeing hugepages of the following types:
- hugepage on shared memory,
- anonymous hugepage,
- filebacked hugepage.

And also add read/write helper functions.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/tsrc/hugepage.h b/tsrc/hugepage.h
new file mode 100644
index 0000000..c2ff779
--- /dev/null
+++ b/tsrc/hugepage.h
@@ -0,0 +1,162 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+int HPS;
+#define err(x) perror(x), exit(1)
+#define errmsg(x) fprintf(stderr, x), exit(1)
+
+void write_hugepage(char *addr, int size, char *avoid)
+{
+	int i, j;
+	for (i = 0; i < size; i++) {
+		if (addr == avoid)
+			continue;
+		for (j = 0; j < HPS; j++) {
+			*(addr + i * HPS + j) = (char)('a' + ((i + j) % 26));
+		}
+	}
+}
+
+/* return -1 if buffer content differs from the expected ones */
+int read_hugepage(char *addr, int size, char *avoid)
+{
+	int i, j;
+	int ret = 0;
+
+	for (i = 0; i < size; i++) {
+		if (addr == avoid)
+			continue;
+		for (j = 0; j < HPS; j++) {
+			if (*(addr + i * HPS + j) != (char)('a' + ((i + j) % 26))) {
+				printf("Mismatch at %d\n", i + j);
+				ret = -1;
+				break;
+			}
+		}
+	}
+	return ret;
+}
+
+int hugetlbfs_root(char *dir)
+{
+	int found = 0;
+	FILE *f = fopen("/proc/mounts", "r");
+	if (!f) err("open /proc/mounts");
+	char *line = NULL;
+	size_t linelen = 0;
+	char dummy[100];
+	while (getline(&line, &linelen, f) > 0) {
+		if (sscanf(line, "none %s hugetlbfs %[^ ]",
+			   dir, dummy) >= 2) {
+			found = 1;
+			break;
+		}
+	}
+	free(line);
+	fclose(f);
+	if (!found)
+		printf("cannot find hugetlbfs directory in /proc/mounts\n");
+	return found;
+}
+
+void *alloc_shm_hugepage(int *key, int size)
+{
+	void *addr;
+	int shmid;
+	if ((shmid = shmget(*key, size,
+			    SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) {
+		perror("shmget");
+		return NULL;
+	}
+	addr = shmat(shmid, (void *)0x0UL, 0);
+	if (addr == (char *)-1) {
+		perror("Shared memory attach failure");
+		shmctl(shmid, IPC_RMID, NULL);
+		return NULL;
+	}
+	*key = shmid;
+	return addr;
+}
+
+void *alloc_anonymous_hugepage(int size, int private)
+{
+	void *addr;
+	int mapflag = MAP_ANONYMOUS | 0x40000; /* MAP_HUGETLB */
+	if (private)
+		mapflag |= MAP_PRIVATE;
+	else
+		mapflag |= MAP_SHARED;
+	if ((addr = mmap(0, size,
+			 PROT_READ|PROT_WRITE, mapflag, -1, 0)) == MAP_FAILED) {
+		perror("mmap");
+		return NULL;
+	}
+	return addr;
+}
+
+void *alloc_filebacked_hugepage(char *filepath, int size, int private, int *fd)
+{
+	int mapflag = MAP_SHARED;
+	void *addr;
+	if (private)
+		mapflag = MAP_PRIVATE;
+	if ((*fd = open(filepath, O_CREAT | O_RDWR, 0777)) < 0) {
+		perror("open");
+		return NULL;
+	}
+	if ((addr = mmap(0, size,
+			 PROT_READ|PROT_WRITE, mapflag, *fd, 0)) == MAP_FAILED) {
+		perror("mmap");
+		unlink(filepath);
+		return NULL;
+	}
+	return addr;
+}
+
+int free_shm_hugepage(int key, void *addr)
+{
+	if (shmdt((const void *)addr) != 0) {
+		perror("Detach failure");
+		shmctl(key, IPC_RMID, NULL);
+		return -1;
+	}
+	shmctl(key, IPC_RMID, NULL);
+	return 0;
+}
+
+int free_anonymous_hugepage(void *addr, int size)
+{
+	int ret = 0;
+	if (munmap(addr, size)) {
+		perror("munmap");
+		ret = -1;
+	}
+	return ret;
+}
+
+int free_filebacked_hugepage(void *addr, int size, int fd, char *filepath)
+{
+	int ret = 0;
+	if (munmap(addr, size)) {
+		perror("munmap");
+		ret = -1;
+	}
+	if (close(fd)) {
+		perror("close");
+		ret = -1;
+	}
+	if (filepath) {
+		if (unlink(filepath)) {
+			perror("unlink");
+			ret = -1;
+		}
+	} else {
+		fprintf(stderr, "Filepath not specified.\n");
+		ret = -1;
+	}
+	return ret;
+}