1 files changed, 130 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/transhuge-stress.c b/tools/testing/selftests/mm/transhuge-stress.c
new file mode 100644
index 0000000000..c61fb9350b
--- /dev/null
+++ b/tools/testing/selftests/mm/transhuge-stress.c
@@ -0,0 +1,130 @@
+/*
+ * Stress test for transparent huge pages, memory compaction and migration.
+ *
+ * Authors: Konstantin Khlebnikov <koct9i@gmail.com>
+ *
+ * This is free and unencumbered software released into the public domain.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <err.h>
+#include <time.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/mman.h>
+#include "vm_util.h"
+
+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 start, a, b;
+	int i = 0;
+	char *name = NULL;
+	double s;
+	uint8_t *map;
+	size_t map_len;
+	int pagemap_fd;
+	int duration = 0;
+
+	ram = sysconf(_SC_PHYS_PAGES);
+	if (ram > SIZE_MAX / psize() / 4)
+		ram = SIZE_MAX / 4;
+	else
+		ram *= psize();
+	len = ram;
+
+	while (++i < argc) {
+		if (!strcmp(argv[i], "-h"))
+			errx(1, "usage: %s [-f <filename>] [-d <duration>] [size in MiB]", argv[0]);
+		else if (!strcmp(argv[i], "-f"))
+			name = argv[++i];
+		else if (!strcmp(argv[i], "-d"))
+			duration = atoi(argv[++i]);
+		else
+			len = atoll(argv[i]) << 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,
+	      ram >> (20 + HPAGE_SHIFT - pshift() - 1));
+
+	pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
+	if (pagemap_fd < 0)
+		err(2, "open pagemap");
+
+	len -= len % HPAGE_SIZE;
+	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;
+
+	if (madvise(ptr, len, MADV_HUGEPAGE))
+		err(2, "MADV_HUGEPAGE");
+
+	map_len = ram >> (HPAGE_SHIFT - 1);
+	map = malloc(map_len);
+	if (!map)
+		errx(2, "map malloc");
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+
+	while (1) {
+		int nr_succeed = 0, nr_failed = 0, nr_pages = 0;
+
+		memset(map, 0, map_len);
+
+		clock_gettime(CLOCK_MONOTONIC, &a);
+		for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
+			int64_t pfn;
+
+			pfn = allocate_transhuge(p, pagemap_fd);
+
+			if (pfn < 0) {
+				nr_failed++;
+			} else {
+				size_t idx = pfn >> (HPAGE_SHIFT - pshift());
+
+				nr_succeed++;
+				if (idx >= map_len) {
+					map = realloc(map, idx + 1);
+					if (!map)
+						errx(2, "map realloc");
+					memset(map + map_len, 0, idx + 1 - map_len);
+					map_len = idx + 1;
+				}
+				if (!map[idx])
+					nr_pages++;
+				map[idx] = 1;
+			}
+
+			/* split transhuge page, keep last page */
+			if (madvise(p, HPAGE_SIZE - psize(), MADV_DONTNEED))
+				err(2, "MADV_DONTNEED");
+		}
+		clock_gettime(CLOCK_MONOTONIC, &b);
+		s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
+
+		warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
+		      "%4d succeed, %4d failed, %4d different pages",
+		      s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
+		      nr_succeed, nr_failed, nr_pages);
+
+		if (duration > 0 && b.tv_sec - start.tv_sec >= duration)
+			return 0;
+	}
+}