| Message ID | 20230822015501.791637-5-joel@joelfernandes.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Optimize mremap during mutual alignment within PMD | expand |
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>
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; 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"); /*
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(-)