1 files changed, 244 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/thuge-gen.c b/tools/testing/selftests/mm/thuge-gen.c
new file mode 100644
index 000000000000..ea7fd8fe2876
--- /dev/null
+++ b/tools/testing/selftests/mm/thuge-gen.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Test selecting other page sizes for mmap/shmget.
+
+   Before running this huge pages for each huge page size must have been
+   reserved.
+   For large pages beyond MAX_PAGE_ORDER (like 1GB on x86) boot options must
+   be used. 1GB wouldn't be tested if it isn't available.
+   Also shmmax must be increased.
+   And you need to run as root to work around some weird permissions in shm.
+   And nothing using huge pages should run in parallel.
+   When the program aborts you may need to clean up the shm segments with
+   ipcrm -m by hand, like this
+   sudo ipcs | awk '$1 == "0x00000000" {print $2}' | xargs -n1 sudo ipcrm -m
+   (warning this will remove all if someone else uses them) */
+
+#define _GNU_SOURCE 1
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <sys/stat.h>
+#include <glob.h>
+#include <assert.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <string.h>
+#include "vm_util.h"
+#include "../kselftest.h"
+
+#define MAP_HUGE_2MB    (21 << MAP_HUGE_SHIFT)
+#define MAP_HUGE_1GB    (30 << MAP_HUGE_SHIFT)
+#define MAP_HUGE_SHIFT  26
+#define MAP_HUGE_MASK   0x3f
+#if !defined(MAP_HUGETLB)
+#define MAP_HUGETLB	0x40000
+#endif
+
+#define SHM_HUGETLB     04000   /* segment will use huge TLB pages */
+#define SHM_HUGE_SHIFT  26
+#define SHM_HUGE_MASK   0x3f
+#define SHM_HUGE_2MB    (21 << SHM_HUGE_SHIFT)
+#define SHM_HUGE_1GB    (30 << SHM_HUGE_SHIFT)
+
+#define NUM_PAGESIZES   5
+#define NUM_PAGES 4
+
+unsigned long page_sizes[NUM_PAGESIZES];
+int num_page_sizes;
+
+int ilog2(unsigned long v)
+{
+	int l = 0;
+	while ((1UL << l) < v)
+		l++;
+	return l;
+}
+
+void show(unsigned long ps)
+{
+	char buf[100];
+
+	if (ps == getpagesize())
+		return;
+
+	ksft_print_msg("%luMB: ", ps >> 20);
+
+	fflush(stdout);
+	snprintf(buf, sizeof buf,
+		"cat /sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
+		ps >> 10);
+	system(buf);
+}
+
+unsigned long read_sysfs(int warn, char *fmt, ...)
+{
+	char *line = NULL;
+	size_t linelen = 0;
+	char buf[100];
+	FILE *f;
+	va_list ap;
+	unsigned long val = 0;
+
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof buf, fmt, ap);
+	va_end(ap);
+
+	f = fopen(buf, "r");
+	if (!f) {
+		if (warn)
+			ksft_print_msg("missing %s\n", buf);
+		return 0;
+	}
+	if (getline(&line, &linelen, f) > 0) {
+		sscanf(line, "%lu", &val);
+	}
+	fclose(f);
+	free(line);
+	return val;
+}
+
+unsigned long read_free(unsigned long ps)
+{
+	return read_sysfs(ps != getpagesize(),
+			  "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
+			  ps >> 10);
+}
+
+void test_mmap(unsigned long size, unsigned flags)
+{
+	char *map;
+	unsigned long before, after;
+
+	before = read_free(size);
+	map = mmap(NULL, size*NUM_PAGES, PROT_READ|PROT_WRITE,
+			MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB|flags, -1, 0);
+	if (map == MAP_FAILED)
+		ksft_exit_fail_msg("mmap: %s\n", strerror(errno));
+
+	memset(map, 0xff, size*NUM_PAGES);
+	after = read_free(size);
+
+	show(size);
+	ksft_test_result(size == getpagesize() || (before - after) == NUM_PAGES,
+			 "%s mmap\n", __func__);
+
+	if (munmap(map, size * NUM_PAGES))
+		ksft_exit_fail_msg("%s: unmap %s\n", __func__, strerror(errno));
+}
+
+void test_shmget(unsigned long size, unsigned flags)
+{
+	int id;
+	unsigned long before, after;
+	struct shm_info i;
+	char *map;
+
+	before = read_free(size);
+	id = shmget(IPC_PRIVATE, size * NUM_PAGES, IPC_CREAT|0600|flags);
+	if (id < 0) {
+		if (errno == EPERM) {
+			ksft_test_result_skip("shmget requires root privileges: %s\n",
+					      strerror(errno));
+			return;
+		}
+		ksft_exit_fail_msg("shmget: %s\n", strerror(errno));
+	}
+
+	if (shmctl(id, SHM_INFO, (void *)&i) < 0)
+		ksft_exit_fail_msg("shmctl: %s\n", strerror(errno));
+
+	map = shmat(id, NULL, 0600);
+	if (map == MAP_FAILED)
+		ksft_exit_fail_msg("shmat: %s\n", strerror(errno));
+
+	shmctl(id, IPC_RMID, NULL);
+
+	memset(map, 0xff, size*NUM_PAGES);
+	after = read_free(size);
+
+	show(size);
+	ksft_test_result(size == getpagesize() || (before - after) == NUM_PAGES,
+			 "%s: mmap\n", __func__);
+	if (shmdt(map))
+		ksft_exit_fail_msg("%s: shmdt: %s\n", __func__, strerror(errno));
+}
+
+void find_pagesizes(void)
+{
+	unsigned long largest = getpagesize();
+	int i;
+	glob_t g;
+
+	glob("/sys/kernel/mm/hugepages/hugepages-*kB", 0, NULL, &g);
+	assert(g.gl_pathc <= NUM_PAGESIZES);
+	for (i = 0; (i < g.gl_pathc) && (num_page_sizes < NUM_PAGESIZES); i++) {
+		sscanf(g.gl_pathv[i], "/sys/kernel/mm/hugepages/hugepages-%lukB",
+				&page_sizes[num_page_sizes]);
+		page_sizes[num_page_sizes] <<= 10;
+		ksft_print_msg("Found %luMB\n", page_sizes[i] >> 20);
+
+		if (page_sizes[num_page_sizes] > largest)
+			largest = page_sizes[i];
+
+		if (read_free(page_sizes[num_page_sizes]) >= NUM_PAGES)
+			num_page_sizes++;
+		else
+			ksft_print_msg("SKIP for size %lu MB as not enough huge pages, need %u\n",
+				       page_sizes[num_page_sizes] >> 20, NUM_PAGES);
+	}
+	globfree(&g);
+
+	if (read_sysfs(0, "/proc/sys/kernel/shmmax") < NUM_PAGES * largest)
+		ksft_exit_fail_msg("Please do echo %lu > /proc/sys/kernel/shmmax",
+				   largest * NUM_PAGES);
+
+#if defined(__x86_64__)
+	if (largest != 1U<<30) {
+		ksft_exit_fail_msg("No GB pages available on x86-64\n"
+				   "Please boot with hugepagesz=1G hugepages=%d\n", NUM_PAGES);
+	}
+#endif
+}
+
+int main(void)
+{
+	unsigned default_hps = default_huge_page_size();
+	int i;
+
+	ksft_print_header();
+
+	find_pagesizes();
+
+	if (!num_page_sizes)
+		ksft_finished();
+
+	ksft_set_plan(2 * num_page_sizes + 3);
+
+	for (i = 0; i < num_page_sizes; i++) {
+		unsigned long ps = page_sizes[i];
+		int arg = ilog2(ps) << MAP_HUGE_SHIFT;
+
+		ksft_print_msg("Testing %luMB mmap with shift %x\n", ps >> 20, arg);
+		test_mmap(ps, MAP_HUGETLB | arg);
+	}
+
+	ksft_print_msg("Testing default huge mmap\n");
+	test_mmap(default_hps, MAP_HUGETLB);
+
+	ksft_print_msg("Testing non-huge shmget\n");
+	test_shmget(getpagesize(), 0);
+
+	for (i = 0; i < num_page_sizes; i++) {
+		unsigned long ps = page_sizes[i];
+		int arg = ilog2(ps) << SHM_HUGE_SHIFT;
+		ksft_print_msg("Testing %luMB shmget with shift %x\n", ps >> 20, arg);
+		test_shmget(ps, SHM_HUGETLB | arg);
+	}
+
+	ksft_print_msg("default huge shmget\n");
+	test_shmget(default_hps, SHM_HUGETLB);
+
+	ksft_finished();
+}