On Tue, Aug 22, 2023 at 01:54:57AM +0000, Joel Fernandes (Google) wrote:
This patch adds a test case to check if a PMD-alignment optimization successfully happens.
I add support to make sure there is some room before the source mapping, otherwise the optimization to trigger PMD-aligned move will be disabled as the kernel will detect that a mapping before the source exists and such optimization becomes impossible.
Signed-off-by: Joel Fernandes (Google) joel@joelfernandes.org
tools/testing/selftests/mm/mremap_test.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c index 6822d657f589..6304eb0947a3 100644 --- a/tools/testing/selftests/mm/mremap_test.c +++ b/tools/testing/selftests/mm/mremap_test.c @@ -44,6 +44,7 @@ enum { _1MB = 1ULL << 20, _2MB = 2ULL << 20, _4MB = 4ULL << 20,
- _5MB = 5ULL << 20, _1GB = 1ULL << 30, _2GB = 2ULL << 30, PMD = _2MB,
@@ -235,6 +236,11 @@ static void *get_source_mapping(struct config c) unsigned long long mmap_min_addr;
mmap_min_addr = get_mmap_min_addr();
- /*
* For some tests, we need to not have any mappings below the
* source mapping. Add some headroom to mmap_min_addr for this.
*/
- mmap_min_addr += 10 * _4MB;
To be super nitty, you _in theory_ can't necessarily rely on arbitrary VAs being available even ones at a location that is the very opposite of where mappings will go by default.
I guess the _ideal_ solution would be to PROT_NONE map a range to ensure it's there then munmap() bits you don't want to exist, but that'd involve reworking this whole test and yeah, not worth it.
retry: addr += c.src_alignment; @@ -434,7 +440,7 @@ static int parse_args(int argc, char **argv, unsigned int *threshold_mb, return 0; }
-#define MAX_TEST 13 +#define MAX_TEST 14 #define MAX_PERF_TEST 3 int main(int argc, char **argv) { @@ -500,6 +506,10 @@ int main(int argc, char **argv) test_cases[12] = MAKE_TEST(PUD, PUD, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS, "2GB mremap - Source PUD-aligned, Destination PUD-aligned");
- /* Src and Dest addr 1MB aligned. 5MB mremap. */
- test_cases[13] = MAKE_TEST(_1MB, _1MB, _5MB, NON_OVERLAPPING, EXPECT_SUCCESS,
"5MB mremap - Source 1MB-aligned, Destination 1MB-aligned");
- perf_test_cases[0] = MAKE_TEST(page_size, page_size, _1GB, NON_OVERLAPPING, EXPECT_SUCCESS, "1GB mremap - Source PTE-aligned, Destination PTE-aligned"); /*
-- 2.42.0.rc1.204.g551eb34607-goog
Reviewed-by: Lorenzo Stoakes lstoakes@gmail.com