| Message ID | 20250318174343.243631-2-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/3] selftests/mm: Fix half_ufd_size_MB calculation | expand |
On Tue, Mar 18, 2025 at 05:43:40PM +0000, Ryan Roberts wrote: > uffd-unit-tests uses a memory area with a fixed 32M size. Then it > calculates the number of pages by dividing by page_size, which itself is > either the base page size or the PMD huge page size depending on the > test config. For the latter, we end up with nr_pages=1 for arm64 16K > base pages, and nr_pages=0 for 64K base pages. This doesn't end well. > > So let's make the 32M size a floor and also ensure that we have at least > 2 pages given the PMD size. With this change, the tests pass on arm64 > 64K base page size configuration. > > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Peter Xu <peterx@redhat.com>
On Tue, Mar 18, 2025 at 05:43:40PM +0000, Ryan Roberts wrote: > uffd-unit-tests uses a memory area with a fixed 32M size. Then it > calculates the number of pages by dividing by page_size, which itself is > either the base page size or the PMD huge page size depending on the > test config. For the latter, we end up with nr_pages=1 for arm64 16K > base pages, and nr_pages=0 for 64K base pages. This doesn't end well. > > So let's make the 32M size a floor and also ensure that we have at least > 2 pages given the PMD size. With this change, the tests pass on arm64 > 64K base page size configuration. > > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > tools/testing/selftests/mm/uffd-unit-tests.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c > index 74c8bc02b506..6973e57b227a 100644 > --- a/tools/testing/selftests/mm/uffd-unit-tests.c > +++ b/tools/testing/selftests/mm/uffd-unit-tests.c > @@ -26,6 +26,8 @@ > #define ALIGN_UP(x, align_to) \ > ((__typeof__(x))((((unsigned long)(x)) + ((align_to)-1)) & ~((align_to)-1))) > > +#define MAX(a, b) (((a) > (b)) ? (a) : (b)) > + > struct mem_type { > const char *name; > unsigned int mem_flag; > @@ -196,7 +198,8 @@ uffd_setup_environment(uffd_test_args_t *args, uffd_test_case_t *test, > else > page_size = psize(); > > - nr_pages = UFFD_TEST_MEM_SIZE / page_size; > + /* Ensure we have at least 2 pages */ > + nr_pages = MAX(UFFD_TEST_MEM_SIZE, page_size * 2) / page_size; > /* TODO: remove this global var.. it's so ugly */ > nr_cpus = 1; > > -- > 2.43.0 > Acked-by: Rafael Aquini <raquini@redhat.com>
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 74c8bc02b506..6973e57b227a 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -26,6 +26,8 @@ #define ALIGN_UP(x, align_to) \ ((__typeof__(x))((((unsigned long)(x)) + ((align_to)-1)) & ~((align_to)-1))) +#define MAX(a, b) (((a) > (b)) ? (a) : (b)) + struct mem_type { const char *name; unsigned int mem_flag; @@ -196,7 +198,8 @@ uffd_setup_environment(uffd_test_args_t *args, uffd_test_case_t *test, else page_size = psize(); - nr_pages = UFFD_TEST_MEM_SIZE / page_size; + /* Ensure we have at least 2 pages */ + nr_pages = MAX(UFFD_TEST_MEM_SIZE, page_size * 2) / page_size; /* TODO: remove this global var.. it's so ugly */ nr_cpus = 1;
uffd-unit-tests uses a memory area with a fixed 32M size. Then it calculates the number of pages by dividing by page_size, which itself is either the base page size or the PMD huge page size depending on the test config. For the latter, we end up with nr_pages=1 for arm64 16K base pages, and nr_pages=0 for 64K base pages. This doesn't end well. So let's make the 32M size a floor and also ensure that we have at least 2 pages given the PMD size. With this change, the tests pass on arm64 64K base page size configuration. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- tools/testing/selftests/mm/uffd-unit-tests.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)