The patch titled
Subject: selftest/mm: ksm_functional_tests: refactor mmap_and_merge_range()
has been added to the -mm mm-unstable branch. Its filename is
selftest-mm-ksm_functional_tests-refactor-mmap_and_merge_range.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftest-mm-ksm_functional_tests-refactor-mmap_and_merge_range.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
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branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Jinjiang Tu <tujinjiang@xxxxxxxxxx>
Subject: selftest/mm: ksm_functional_tests: refactor mmap_and_merge_range()
Date: Thu, 28 Mar 2024 19:10:09 +0800
In order to extend test_prctl_fork() and test_prctl_fork_exec() to make
sure that deduplication really happens, mmap_and_merge_range() needs to be
refactored.
Firstly, mmap_and_merge_range() will be called with no need to call enable
KSM by madvise or prctl. So, switch the 'bool use_prctl' parameter to
enum ksm_merge_mode.
Secondly, mmap_and_merge_range() will be called in child process in the
two testcases, it isn't appropriate to call ksft_test_result_{fail, skip},
because the global variables ksft_{fail, skip} aren't consistent with the
parent process. Thus, convert calls of ksft_test_result_{fail, skip} to
ksft_print_msg(), return differrent error according to the two cases, and
rename mmap_and_merge_range() to __mmap_and_merge_range(). For existing
callers, introduce new mmap_and_merge_range() to handle different return
values of __mmap_and_merge_range().
Link: https://lkml.kernel.org/r/20240328111010.1502191-3-tujinjiang@xxxxxxxxxx
Signed-off-by: Jinjiang Tu <tujinjiang@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Stefan Roesch <shr@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/ksm_functional_tests.c | 86 ++++++++----
1 file changed, 61 insertions(+), 25 deletions(-)
--- a/tools/testing/selftests/mm/ksm_functional_tests.c~selftest-mm-ksm_functional_tests-refactor-mmap_and_merge_range
+++ a/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -28,6 +28,15 @@
#define MiB (1024 * KiB)
#define FORK_EXEC_CHILD_PRG_NAME "ksm_fork_exec_child"
+#define MAP_MERGE_FAIL ((void *)-1)
+#define MAP_MERGE_SKIP ((void *)-2)
+
+enum ksm_merge_mode {
+ KSM_MERGE_PRCTL,
+ KSM_MERGE_MADVISE,
+ KSM_MERGE_NONE, /* PRCTL already set */
+};
+
static int mem_fd;
static int ksm_fd;
static int ksm_full_scans_fd;
@@ -146,33 +155,34 @@ static int ksm_unmerge(void)
return 0;
}
-static char *mmap_and_merge_range(char val, unsigned long size, int prot,
- bool use_prctl)
+static char *__mmap_and_merge_range(char val, unsigned long size, int prot,
+ enum ksm_merge_mode mode)
{
char *map;
+ char *err_map = MAP_MERGE_FAIL;
int ret;
/* Stabilize accounting by disabling KSM completely. */
if (ksm_unmerge()) {
- ksft_test_result_fail("Disabling (unmerging) KSM failed\n");
- return MAP_FAILED;
+ ksft_print_msg("Disabling (unmerging) KSM failed\n");
+ return err_map;
}
if (get_my_merging_pages() > 0) {
- ksft_test_result_fail("Still pages merged\n");
- return MAP_FAILED;
+ ksft_print_msg("Still pages merged\n");
+ return err_map;
}
map = mmap(NULL, size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANON, -1, 0);
if (map == MAP_FAILED) {
- ksft_test_result_fail("mmap() failed\n");
- return MAP_FAILED;
+ ksft_print_msg("mmap() failed\n");
+ return err_map;
}
/* Don't use THP. Ignore if THP are not around on a kernel. */
if (madvise(map, size, MADV_NOHUGEPAGE) && errno != EINVAL) {
- ksft_test_result_fail("MADV_NOHUGEPAGE failed\n");
+ ksft_print_msg("MADV_NOHUGEPAGE failed\n");
goto unmap;
}
@@ -180,27 +190,36 @@ static char *mmap_and_merge_range(char v
memset(map, val, size);
if (mprotect(map, size, prot)) {
- ksft_test_result_skip("mprotect() failed\n");
+ ksft_print_msg("mprotect() failed\n");
+ err_map = MAP_MERGE_SKIP;
goto unmap;
}
- if (use_prctl) {
+ switch (mode) {
+ case KSM_MERGE_PRCTL:
ret = prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0);
if (ret < 0 && errno == EINVAL) {
- ksft_test_result_skip("PR_SET_MEMORY_MERGE not supported\n");
+ ksft_print_msg("PR_SET_MEMORY_MERGE not supported\n");
+ err_map = MAP_MERGE_SKIP;
goto unmap;
} else if (ret) {
- ksft_test_result_fail("PR_SET_MEMORY_MERGE=1 failed\n");
+ ksft_print_msg("PR_SET_MEMORY_MERGE=1 failed\n");
goto unmap;
}
- } else if (madvise(map, size, MADV_MERGEABLE)) {
- ksft_test_result_fail("MADV_MERGEABLE failed\n");
- goto unmap;
+ break;
+ case KSM_MERGE_MADVISE:
+ if (madvise(map, size, MADV_MERGEABLE)) {
+ ksft_print_msg("MADV_MERGEABLE failed\n");
+ goto unmap;
+ }
+ break;
+ case KSM_MERGE_NONE:
+ break;
}
/* Run KSM to trigger merging and wait. */
if (ksm_merge()) {
- ksft_test_result_fail("Running KSM failed\n");
+ ksft_print_msg("Running KSM failed\n");
goto unmap;
}
@@ -209,14 +228,31 @@ static char *mmap_and_merge_range(char v
* accounted differently (depending on kernel support).
*/
if (val && !get_my_merging_pages()) {
- ksft_test_result_fail("No pages got merged\n");
+ ksft_print_msg("No pages got merged\n");
goto unmap;
}
return map;
unmap:
munmap(map, size);
- return MAP_FAILED;
+ return err_map;
+}
+
+static char *mmap_and_merge_range(char val, unsigned long size, int prot,
+ enum ksm_merge_mode mode)
+{
+ char *map;
+ char *ret = MAP_FAILED;
+
+ map = __mmap_and_merge_range(val, size, prot, mode);
+ if (map == MAP_MERGE_FAIL)
+ ksft_test_result_fail("Merging memory failed");
+ else if (map == MAP_MERGE_SKIP)
+ ksft_test_result_skip("Merging memory skipped");
+ else
+ ret = map;
+
+ return ret;
}
static void test_unmerge(void)
@@ -226,7 +262,7 @@ static void test_unmerge(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -264,7 +300,7 @@ static void test_unmerge_zero_pages(void
}
/* Let KSM deduplicate zero pages. */
- map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -312,7 +348,7 @@ static void test_unmerge_discarded(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -344,7 +380,7 @@ static void test_unmerge_uffd_wp(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -545,7 +581,7 @@ static void test_prctl_unmerge(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, true);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_PRCTL);
if (map == MAP_FAILED)
return;
@@ -568,7 +604,7 @@ static void test_prot_none(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0x11, size, PROT_NONE, false);
+ map = mmap_and_merge_range(0x11, size, PROT_NONE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
goto unmap;
_
Patches currently in -mm which might be from tujinjiang@xxxxxxxxxx are
mm-ksm-fix-ksm-exec-support-for-prctl.patch
selftest-mm-ksm_functional_tests-refactor-mmap_and_merge_range.patch
selftest-mm-ksm_functional_tests-extend-test-case-for-ksm-fork-exec.patch
