1 files changed, 25 insertions, 47 deletions

diff --git a/tools/testing/selftests/vm/transhuge-stress.c b/tools/testing/selftests/vm/transhuge-stress.c
index 5e4c036f6ad3..e3f00adb1b82 100644
--- a/tools/testing/selftests/vm/transhuge-stress.c
+++ b/tools/testing/selftests/vm/transhuge-stress.c
@@ -15,67 +15,46 @@
 #include <fcntl.h>
 #include <string.h>
 #include <sys/mman.h>
+#include "util.h"
 
-#define PAGE_SHIFT 12
-#define HPAGE_SHIFT 21
-
-#define PAGE_SIZE (1 << PAGE_SHIFT)
-#define HPAGE_SIZE (1 << HPAGE_SHIFT)
-
-#define PAGEMAP_PRESENT(ent)	(((ent) & (1ull << 63)) != 0)
-#define PAGEMAP_PFN(ent)	((ent) & ((1ull << 55) - 1))
-
-int pagemap_fd;
-
-int64_t allocate_transhuge(void *ptr)
-{
-	uint64_t ent[2];
-
-	/* drop pmd */
-	if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
-				MAP_FIXED | MAP_ANONYMOUS |
-				MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
-		errx(2, "mmap transhuge");
-
-	if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
-		err(2, "MADV_HUGEPAGE");
-
-	/* allocate transparent huge page */
-	*(volatile void **)ptr = ptr;
-
-	if (pread(pagemap_fd, ent, sizeof(ent),
-			(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
-		err(2, "read pagemap");
-
-	if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
-	    PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
-	    !(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - PAGE_SHIFT)) - 1)))
-		return PAGEMAP_PFN(ent[0]);
-
-	return -1;
-}
+int backing_fd = -1;
+int mmap_flags = MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE;
+#define PROT_RW (PROT_READ | PROT_WRITE)
 
 int main(int argc, char **argv)
 {
 	size_t ram, len;
 	void *ptr, *p;
 	struct timespec a, b;
+	int i = 0;
+	char *name = NULL;
 	double s;
 	uint8_t *map;
 	size_t map_len;
+	int pagemap_fd;
 
 	ram = sysconf(_SC_PHYS_PAGES);
 	if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4)
 		ram = SIZE_MAX / 4;
 	else
 		ram *= sysconf(_SC_PAGESIZE);
+	len = ram;
+
+	while (++i < argc) {
+		if (!strcmp(argv[i], "-h"))
+			errx(1, "usage: %s [size in MiB]", argv[0]);
+		else if (!strcmp(argv[i], "-f"))
+			name = argv[++i];
+		else
+			len = atoll(argv[i]) << 20;
+	}
 
-	if (argc == 1)
-		len = ram;
-	else if (!strcmp(argv[1], "-h"))
-		errx(1, "usage: %s [size in MiB]", argv[0]);
-	else
-		len = atoll(argv[1]) << 20;
+	if (name) {
+		backing_fd = open(name, O_RDWR);
+		if (backing_fd == -1)
+			errx(2, "open %s", name);
+		mmap_flags = MAP_SHARED;
+	}
 
 	warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
 	      " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
@@ -86,8 +65,7 @@ int main(int argc, char **argv)
 		err(2, "open pagemap");
 
 	len -= len % HPAGE_SIZE;
-	ptr = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
-			MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
+	ptr = mmap(NULL, len + HPAGE_SIZE, PROT_RW, mmap_flags, backing_fd, 0);
 	if (ptr == MAP_FAILED)
 		err(2, "initial mmap");
 	ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
@@ -109,7 +87,7 @@ int main(int argc, char **argv)
 		for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
 			int64_t pfn;
 
-			pfn = allocate_transhuge(p);
+			pfn = allocate_transhuge(p, pagemap_fd);
 
 			if (pfn < 0) {
 				nr_failed++;