From ea7b1dd44867e9cd6bac67e7c9fc3f128b5b255c Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 18 Feb 2011 17:59:12 +0100 Subject: drm: mm: track free areas implicitly The idea is to track free holes implicitly by marking the allocation immediatly preceeding a hole. To avoid an ugly corner case add a dummy head_node to struct drm_mm to track the hole that spans to complete allocation area when the memory manager is empty. To guarantee that there's always a preceeding/following node (that might be marked as hole_follows == 1), move the mm->node_list list_head to the head_node. The main allocator and fair-lru scan code actually becomes simpler. Only the debug code slightly suffers because free areas are no longer explicit. Also add drm_mm_for_each_node (which will be much more useful when struct drm_mm_node is embeddable). Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie --- include/drm/drm_mm.h | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'include/drm') diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h index 0d791462f7b2..34fa36f2de70 100644 --- a/include/drm/drm_mm.h +++ b/include/drm/drm_mm.h @@ -42,23 +42,24 @@ #endif struct drm_mm_node { - struct list_head free_stack; struct list_head node_list; - unsigned free : 1; + struct list_head hole_stack; + unsigned hole_follows : 1; unsigned scanned_block : 1; unsigned scanned_prev_free : 1; unsigned scanned_next_free : 1; + unsigned scanned_preceeds_hole : 1; unsigned long start; unsigned long size; struct drm_mm *mm; }; struct drm_mm { - /* List of free memory blocks, most recently freed ordered. */ - struct list_head free_stack; - /* List of all memory nodes, ordered according to the (increasing) start - * address of the memory node. */ - struct list_head node_list; + /* List of all memory nodes that immediatly preceed a free hole. */ + struct list_head hole_stack; + /* head_node.node_list is the list of all memory nodes, ordered + * according to the (increasing) start address of the memory node. */ + struct drm_mm_node head_node; struct list_head unused_nodes; int num_unused; spinlock_t unused_lock; @@ -74,9 +75,11 @@ struct drm_mm { static inline bool drm_mm_initialized(struct drm_mm *mm) { - return mm->free_stack.next; + return mm->hole_stack.next; } - +#define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \ + &(mm)->head_node.node_list, \ + node_list); /* * Basic range manager support (drm_mm.c) */ -- cgit v1.2.3