From: Arunpravin Paneer Selvam Arunpravin.PaneerSelvam@amd.com
commit 5640e81607152d7f2d2558227c0f6cb78b8f39cf upstream.
We are observing performance drop in many usecases which include games, 3D benchmark applications,etc.. To solve this problem, We are strictly not allowing top down flag enabled allocations to steal the memory space from cpu visible region.
The idea is, we are sorting each order list entries in ascending order and compare the last entry of each order list in the freelist and return the max block.
This patch improves the 3D benchmark scores and solves fragmentation issues.
All drm buddy selftests are verfied. drm_buddy: pass:6 fail:0 skip:0 total:6
Signed-off-by: Arunpravin Paneer Selvam Arunpravin.PaneerSelvam@amd.com Acked-by: Christian König christian.koenig@amd.com Acked-by: Alex Deucher alexander.deucher@amd.com Reviewed-by: Matthew Auld matthew.auld@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20230112120027.3072-1-Arunprav... Signed-off-by: Christian König christian.koenig@amd.com CC: Cc: stable@vger.kernel.org # 5.18+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/drm_buddy.c | 83 +++++++++++++++++++++++++++++--------------- 1 file changed, 55 insertions(+), 28 deletions(-)
--- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -38,6 +38,25 @@ static void drm_block_free(struct drm_bu kmem_cache_free(slab_blocks, block); }
+static void list_insert_sorted(struct drm_buddy *mm, + struct drm_buddy_block *block) +{ + struct drm_buddy_block *node; + struct list_head *head; + + head = &mm->free_list[drm_buddy_block_order(block)]; + if (list_empty(head)) { + list_add(&block->link, head); + return; + } + + list_for_each_entry(node, head, link) + if (drm_buddy_block_offset(block) < drm_buddy_block_offset(node)) + break; + + __list_add(&block->link, node->link.prev, &node->link); +} + static void mark_allocated(struct drm_buddy_block *block) { block->header &= ~DRM_BUDDY_HEADER_STATE; @@ -52,8 +71,7 @@ static void mark_free(struct drm_buddy * block->header &= ~DRM_BUDDY_HEADER_STATE; block->header |= DRM_BUDDY_FREE;
- list_add(&block->link, - &mm->free_list[drm_buddy_block_order(block)]); + list_insert_sorted(mm, block); }
static void mark_split(struct drm_buddy_block *block) @@ -387,20 +405,26 @@ err_undo: }
static struct drm_buddy_block * -get_maxblock(struct list_head *head) +get_maxblock(struct drm_buddy *mm, unsigned int order) { struct drm_buddy_block *max_block = NULL, *node; + unsigned int i;
- max_block = list_first_entry_or_null(head, - struct drm_buddy_block, - link); - if (!max_block) - return NULL; - - list_for_each_entry(node, head, link) { - if (drm_buddy_block_offset(node) > - drm_buddy_block_offset(max_block)) - max_block = node; + for (i = order; i <= mm->max_order; ++i) { + if (!list_empty(&mm->free_list[i])) { + node = list_last_entry(&mm->free_list[i], + struct drm_buddy_block, + link); + if (!max_block) { + max_block = node; + continue; + } + + if (drm_buddy_block_offset(node) > + drm_buddy_block_offset(max_block)) { + max_block = node; + } + } }
return max_block; @@ -412,20 +436,23 @@ alloc_from_freelist(struct drm_buddy *mm unsigned long flags) { struct drm_buddy_block *block = NULL; - unsigned int i; + unsigned int tmp; int err;
- for (i = order; i <= mm->max_order; ++i) { - if (flags & DRM_BUDDY_TOPDOWN_ALLOCATION) { - block = get_maxblock(&mm->free_list[i]); - if (block) - break; - } else { - block = list_first_entry_or_null(&mm->free_list[i], - struct drm_buddy_block, - link); - if (block) - break; + if (flags & DRM_BUDDY_TOPDOWN_ALLOCATION) { + block = get_maxblock(mm, order); + if (block) + /* Store the obtained block order */ + tmp = drm_buddy_block_order(block); + } else { + for (tmp = order; tmp <= mm->max_order; ++tmp) { + if (!list_empty(&mm->free_list[tmp])) { + block = list_last_entry(&mm->free_list[tmp], + struct drm_buddy_block, + link); + if (block) + break; + } } }
@@ -434,18 +461,18 @@ alloc_from_freelist(struct drm_buddy *mm
BUG_ON(!drm_buddy_block_is_free(block));
- while (i != order) { + while (tmp != order) { err = split_block(mm, block); if (unlikely(err)) goto err_undo;
block = block->right; - i--; + tmp--; } return block;
err_undo: - if (i != order) + if (tmp != order) __drm_buddy_free(mm, block); return ERR_PTR(err); }