create a pot-sized mm, then allocate one of each possible
order within. This should leave the mm with exactly one
page left.
Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx>
---
.../gpu/drm/selftests/drm_buddy_selftests.h | 1 +
drivers/gpu/drm/selftests/test-drm_buddy.c | 153 ++++++++++++++++++
2 files changed, 154 insertions(+)
diff --git a/drivers/gpu/drm/selftests/drm_buddy_selftests.h b/drivers/gpu/drm/selftests/drm_buddy_selftests.h
index 21a6bd38864f..b14f04a1de19 100644
--- a/drivers/gpu/drm/selftests/drm_buddy_selftests.h
+++ b/drivers/gpu/drm/selftests/drm_buddy_selftests.h
@@ -10,3 +10,4 @@ selftest(sanitycheck, igt_sanitycheck) /* keep first (selfcheck for igt) */
selftest(buddy_alloc_limit, igt_buddy_alloc_limit)
selftest(buddy_alloc_range, igt_buddy_alloc_range)
selftest(buddy_alloc_optimistic, igt_buddy_alloc_optimistic)
+selftest(buddy_alloc_pessimistic, igt_buddy_alloc_pessimistic)
diff --git a/drivers/gpu/drm/selftests/test-drm_buddy.c b/drivers/gpu/drm/selftests/test-drm_buddy.c
index b193d9556fb4..e97f583ed0cd 100644
--- a/drivers/gpu/drm/selftests/test-drm_buddy.c
+++ b/drivers/gpu/drm/selftests/test-drm_buddy.c
@@ -314,6 +314,159 @@ static void igt_mm_config(u64 *size, u64 *chunk_size)
*size = (u64)s << 12;
}
+static int igt_buddy_alloc_pessimistic(void *arg)
+{
+ u64 mm_size, size, min_page_size, start = 0;
+ struct drm_buddy_block *block, *bn;
+ const unsigned int max_order = 16;
+ unsigned long flags = 0;
+ struct drm_buddy mm;
+ unsigned int order;
+ LIST_HEAD(blocks);
+ LIST_HEAD(tmp);
+ int err;
+
+ /*
+ * Create a pot-sized mm, then allocate one of each possible
+ * order within. This should leave the mm with exactly one
+ * page left.
+ */
+
+ mm_size = PAGE_SIZE << max_order;
+ err = drm_buddy_init(&mm, mm_size, PAGE_SIZE);
+ if (err) {
+ pr_err("buddy_init failed(%d)\n", err);
+ return err;
+ }
+ BUG_ON(mm.max_order != max_order);
+
+ for (order = 0; order < max_order; order++) {
+ size = min_page_size = get_size(order, PAGE_SIZE);
+ err = drm_buddy_alloc_blocks(&mm, start, mm_size, size, min_page_size, &tmp, flags);
+ if (err) {
+ pr_info("buddy_alloc hit -ENOMEM with order=%d\n",
+ order);
+ goto err;
+ }
+
+ block = list_first_entry_or_null(&tmp,
+ struct drm_buddy_block,
+ link);
+ if (!block) {
+ pr_err("alloc_blocks has no blocks\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ list_del(&block->link);
+ list_add_tail(&block->link, &blocks);
+ }
+
+ /* And now the last remaining block available */
+ size = min_page_size = get_size(0, PAGE_SIZE);
+ err = drm_buddy_alloc_blocks(&mm, start, mm_size, size, min_page_size, &tmp, flags);
+ if (err) {
+ pr_info("buddy_alloc hit -ENOMEM on final alloc\n");
+ goto err;
+ }
+
+ block = list_first_entry_or_null(&tmp,
+ struct drm_buddy_block,
+ link);
+ if (!block) {
+ pr_err("alloc_blocks has no blocks\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ list_del(&block->link);
+ list_add_tail(&block->link, &blocks);
+
+ /* Should be completely full! */
+ for (order = max_order; order--; ) {
+ size = min_page_size = get_size(order, PAGE_SIZE);
+ err = drm_buddy_alloc_blocks(&mm, start, mm_size, size, min_page_size, &tmp, flags);
+ if (!err) {
+ pr_info("buddy_alloc unexpectedly succeeded at order %d, it should be full!",
+ order);
+ block = list_first_entry_or_null(&tmp,
+ struct drm_buddy_block,
+ link);
+ if (!block) {
+ pr_err("alloc_blocks has no blocks\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ list_del(&block->link);
+ list_add_tail(&block->link, &blocks);
+ err = -EINVAL;
+ goto err;
+ }
+ }
+
+ block = list_last_entry(&blocks, typeof(*block), link);
+ list_del(&block->link);
+ drm_buddy_free_block(&mm, block);
+
+ /* As we free in increasing size, we make available larger blocks */
+ order = 1;
+ list_for_each_entry_safe(block, bn, &blocks, link) {
+ list_del(&block->link);
+ drm_buddy_free_block(&mm, block);
+
+ size = min_page_size = get_size(order, PAGE_SIZE);
+ err = drm_buddy_alloc_blocks(&mm, start, mm_size, size, min_page_size, &tmp, flags);
+ if (err) {
+ pr_info("buddy_alloc (realloc) hit -ENOMEM with order=%d\n",
+ order);
+ goto err;
+ }
+
+ block = list_first_entry_or_null(&tmp,
+ struct drm_buddy_block,
+ link);
+ if (!block) {
+ pr_err("alloc_blocks has no blocks\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ list_del(&block->link);
+ drm_buddy_free_block(&mm, block);
+ order++;
+ }
+
+ /* To confirm, now the whole mm should be available */
+ size = min_page_size = get_size(max_order, PAGE_SIZE);
+ err = drm_buddy_alloc_blocks(&mm, start, mm_size, size, min_page_size, &tmp, flags);
+ if (err) {
+ pr_info("buddy_alloc (realloc) hit -ENOMEM with order=%d\n",
+ max_order);
+ goto err;
+ }
+
+ block = list_first_entry_or_null(&tmp,
+ struct drm_buddy_block,
+ link);
+ if (!block) {
+ pr_err("alloc_blocks has no blocks\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ list_del(&block->link);
+ drm_buddy_free_block(&mm, block);
+
+ if (!err)
