On 13/07/2023 15:09, David Hildenbrand wrote:
On 13.07.23 16:03, Ryan Roberts wrote:
On 13/07/2023 14:56, David Hildenbrand wrote:
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@arm.com
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.
Yeah I thought about doing it that way, but then the output just looks like there were fewer tests and they all passed. But thinking about it now, I guess the TAP header outputs the number of planned tests and the number of tests executed are fewer, so a machine parser would still notice. I just don't like that it outputs skipped:0.
But it a lightly held view. Happy to just do:
if (system_has_softdirty()) test_softdirty()
If you insist. ;-)
diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index 60547245e479..33fda0337b32 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -266,12 +266,16 @@ static void test_softdirty(void) int main(int argc, char **argv) { + int nr_tests = 16; int err; pagesize = getpagesize(); + if (system_has_softdirty()) + nr_tests += 5;
This is the opposite of the point I was trying to make; If there are 21 tests in a suite, I'd like to know that there are 21 tests, 16 of which passed and 5 of which were skipped. This will hide the 5 from the test report.
ksft_print_header(); - ksft_set_plan(21); + ksft_set_plan(nr_tests); sense_support(); test_prot_read(); @@ -279,7 +283,8 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - test_softdirty(); + if (system_has_softdirty()) + test_softdirty(); err = ksft_get_fail_cnt(); if (err)