On 13.07.23 15:54, Ryan Roberts wrote:
arm64 does not support the soft-dirty PTE bit. However there are tests
in `madv_populate` and `soft-dirty` which assume it is supported and
cause spurious failures to be reported when preferred behaviour would be
to mark the tests as skipped.
Unfortunately, the only way to determine if the soft-dirty dirty bit is
supported is to write to a page, then see if the bit is set in
/proc/self/pagemap. But the tests that we want to conditionally execute
are testing precicesly this. So if we introduced this feature check, we
could accedentally turn a real failure (on a system that claims to
support soft-dirty) into a skip.
So instead, do the check based on architecture; for arm64, we report
that soft-dirty is not supported. This is wrapped up into a utility
function `system_has_softdirty()`, which is used to skip the whole
`soft-dirty` suite, and mark the soft-dirty tests in the `madv_populate`
suite as skipped.
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
---
tools/testing/selftests/mm/madv_populate.c | 18 +++++++++++++-----
tools/testing/selftests/mm/soft-dirty.c | 3 +++
tools/testing/selftests/mm/vm_util.c | 17 +++++++++++++++++
tools/testing/selftests/mm/vm_util.h | 1 +
4 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c
index 60547245e479..5a8c176d7fec 100644
--- a/tools/testing/selftests/mm/madv_populate.c
+++ b/tools/testing/selftests/mm/madv_populate.c
@@ -232,6 +232,14 @@ static bool range_is_not_softdirty(char *start, ssize_t size)
return ret;
}
+#define ksft_test_result_if_softdirty(cond, ...) \
+do { \
+ if (system_has_softdirty()) \
+ ksft_test_result(cond, __VA_ARGS__); \
+ else \
+ ksft_test_result_skip(__VA_ARGS__); \
+} while (0)
+
static void test_softdirty(void)
{
char *addr;
@@ -246,19 +254,19 @@ static void test_softdirty(void)
/* Clear any softdirty bits. */
clear_softdirty();
- ksft_test_result(range_is_not_softdirty(addr, SIZE),
+ ksft_test_result_if_softdirty(range_is_not_softdirty(addr, SIZE),
"range is not softdirty\n");
/* Populating READ should set softdirty. */
ret = madvise(addr, SIZE, MADV_POPULATE_READ);
- ksft_test_result(!ret, "MADV_POPULATE_READ\n");
- ksft_test_result(range_is_not_softdirty(addr, SIZE),
+ ksft_test_result_if_softdirty(!ret, "MADV_POPULATE_READ\n");
+ ksft_test_result_if_softdirty(range_is_not_softdirty(addr, SIZE),
"range is not softdirty\n");
/* Populating WRITE should set softdirty. */
ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
- ksft_test_result(!ret, "MADV_POPULATE_WRITE\n");
- ksft_test_result(range_is_softdirty(addr, SIZE),
+ ksft_test_result_if_softdirty(!ret, "MADV_POPULATE_WRITE\n");
+ ksft_test_result_if_softdirty(range_is_softdirty(addr, SIZE),
"range is softdirty\n");
We probably want to skip the whole test_*softdirty* test instead of
adding this (IMHO suboptimal) ksft_test_result_if_softdirty.
--
Cheers,
David / dhildenb
