selftests: mm: add a test for mutually aligned moves > PMD size

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.

Link: https://lkml.kernel.org/r/20230903151328.2981432-5-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c
index 6822d657f58956779d41927e0b5fda066fa5b1c6..6304eb0947a3e2b9d406f7bbbff772a5bb67e11b 100644 (file)
--- 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");
        /*