Muhammad Usama Anjum usama.anjum@collabora.com writes:
new file mode 100644 index 0000000000000..3153ebac6909b --- /dev/null +++ b/tools/testing/selftests/vm/soft-dirty.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdio.h> +#include <string.h> +#include <stdbool.h> +#include <fcntl.h> +#include <stdint.h> +#include <malloc.h> +#include <sys/mman.h> +#include "../kselftest.h" +#include "vm_util.h"
+#define PAGEMAP_FILE_PATH "/proc/self/pagemap" +#define TEST_ITERATIONS 10000
+static void test_simple(int pagemap_fd, int pagesize) +{
- int i;
- char *map;
- map = aligned_alloc(pagesize, pagesize);
- if (!map)
ksft_exit_fail_msg("mmap failed\n");- clear_softdirty();
- for (i = 0 ; i < TEST_ITERATIONS; i++) {
if (pagemap_is_softdirty(pagemap_fd, map) == 1) {ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i);break;}clear_softdirty();// Write something to the page to get the dirty bit enabled on the pagemap[0] = i % 255;
you don't need this mod at all but at least it should be 256 :). I think Either 'map[0] = !map[0]' or keeping the original 'map[0]++' is fine.
if (pagemap_is_softdirty(pagemap_fd, map) == 0) {ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i);break;}clear_softdirty();- }
- free(map);
- ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__);
+}
+static void test_vma_reuse(int pagemap_fd, int pagesize) +{
- char *map, *map2;
- map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);
- if (map == MAP_FAILED)
ksft_exit_fail_msg("mmap failed");- clear_softdirty();
- /* Write to the page before unmapping and map the same size region again to check
* if same memory region is gotten next time and if dirty bit is preserved across* this type of allocations.*/
This reads weird. It should *not* be preserved across different mappings. Also, we are not testing if the same region is reused, we are depending on it to test the sd bit.
/* Ensures the soft-dirty bit is reset accross different mappings on the same address. */
- map[0]++;
This is inconsistent with the other two tests.
- munmap(map, pagesize);
- map2 = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);
- if (map2 == MAP_FAILED)
ksft_exit_fail_msg("mmap failed");- ksft_test_result(map == map2, "Test %s reused memory location\n", __func__);
if map != map2, the test itself is broken, meaning we should skip it, not fail, i guess.