From: Matthew Auld <matthew.auld@xxxxxxxxx> Sanity check DRM_BUDDY_CONTIGUOUS_ALLOCATION. References: https://gitlab.freedesktop.org/drm/amd/-/issues/3097 Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx> Cc: Limonciello <mario.limonciello@xxxxxxx> Cc: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx> --- drivers/gpu/drm/tests/drm_buddy_test.c | 89 ++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c index ea2af6bd9abe..4215d8b5fcf0 100644 --- a/drivers/gpu/drm/tests/drm_buddy_test.c +++ b/drivers/gpu/drm/tests/drm_buddy_test.c @@ -8,6 +8,7 @@ #include <linux/prime_numbers.h> #include <linux/sched/signal.h> +#include <linux/sizes.h> #include <drm/drm_buddy.h> @@ -18,6 +19,93 @@ static inline u64 get_size(int order, u64 chunk_size) return (1 << order) * chunk_size; } +static void drm_test_buddy_alloc_contiguous(struct kunit *test) +{ + u64 mm_size, ps = SZ_4K, i, n_pages, total; + struct drm_buddy_block *block; + struct drm_buddy mm; + LIST_HEAD(left); + LIST_HEAD(middle); + LIST_HEAD(right); + LIST_HEAD(allocated); + + mm_size = 16 * 3 * SZ_4K; + + KUNIT_EXPECT_FALSE(test, drm_buddy_init(&mm, mm_size, ps)); + + /* + * Idea is to fragment the address space by alternating block + * allocations between three different lists; one for left, middle and + * right. We can then free a list to simulate fragmentation. In + * particular we want to exercise the DRM_BUDDY_CONTIGUOUS_ALLOCATION, + * including the try_harder path. + */ + + i = 0; + n_pages = mm_size / ps; + do { + struct list_head *list; + int slot = i % 3; + + if (slot == 0) + list = &left; + else if (slot == 1) + list = &middle; + else + list = &right; + KUNIT_ASSERT_FALSE_MSG(test, + drm_buddy_alloc_blocks(&mm, 0, mm_size, + ps, ps, list, 0), + "buddy_alloc hit an error size=%d\n", + ps); + } while (++i < n_pages); + + KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 3 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc didn't error size=%d\n", 3 * ps); + + drm_buddy_free_list(&mm, &middle); + KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 3 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc didn't error size=%llu\n", 3 * ps); + KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 2 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc didn't error size=%llu\n", 2 * ps); + + drm_buddy_free_list(&mm, &right); + KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 3 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc didn't error size=%llu\n", 3 * ps); + /* + * At this point we should have enough contiguous space for 2 blocks, + * however they are never buddies (since we freed middle and right) so + * will require the try_harder logic to find them. + */ + KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 2 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc hit an error size=%d\n", 2 * ps); + + drm_buddy_free_list(&mm, &left); + KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size, + 3 * ps, ps, &allocated, + DRM_BUDDY_CONTIGUOUS_ALLOCATION), + "buddy_alloc hit an error size=%d\n", 3 * ps); + + total = 0; + list_for_each_entry(block, &allocated, link) + total += drm_buddy_block_size(&mm, block); + + KUNIT_ASSERT_EQ(test, total, ps * 2 + ps * 3); + + drm_buddy_free_list(&mm, &allocated); + drm_buddy_fini(&mm); +} + static void drm_test_buddy_alloc_pathological(struct kunit *test) { u64 mm_size, size, start = 0; @@ -280,6 +368,7 @@ static struct kunit_case drm_buddy_tests[] = { KUNIT_CASE(drm_test_buddy_alloc_optimistic), KUNIT_CASE(drm_test_buddy_alloc_pessimistic), KUNIT_CASE(drm_test_buddy_alloc_pathological), + KUNIT_CASE(drm_test_buddy_alloc_contiguous), {} }; -- 2.25.1
