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drm: mm: track free areas implicitly

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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 <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Daniel Vetter 2011-02-18 17:59:12 +01:00 committed by Dave Airlie
parent 31a5b8ce8f
commit ea7b1dd448
2 changed files with 223 additions and 258 deletions
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460
drivers/gpu/drm/drm_mm.c
View File

@ -64,8 +64,8 @@ static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
else {
child =
list_entry(mm->unused_nodes.next,
struct drm_mm_node, free_stack);
list_del(&child->free_stack);
struct drm_mm_node, node_list);
list_del(&child->node_list);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
@ -94,126 +94,123 @@ int drm_mm_pre_get(struct drm_mm *mm)
return ret;
}
++mm->num_unused;
list_add_tail(&node->free_stack, &mm->unused_nodes);
list_add_tail(&node->node_list, &mm->unused_nodes);
}
spin_unlock(&mm->unused_lock);
return 0;
}
EXPORT_SYMBOL(drm_mm_pre_get);
static int drm_mm_create_tail_node(struct drm_mm *mm,
unsigned long start,
unsigned long size, int atomic)
static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
{
struct drm_mm_node *child;
child = drm_mm_kmalloc(mm, atomic);
if (unlikely(child == NULL))
return -ENOMEM;
child->free = 1;
child->size = size;
child->start = start;
child->mm = mm;
list_add_tail(&child->node_list, &mm->node_list);
list_add_tail(&child->free_stack, &mm->free_stack);
return 0;
return hole_node->start + hole_node->size;
}
static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
unsigned long size,
int atomic)
static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
{
struct drm_mm_node *child;
struct drm_mm_node *next_node =
list_entry(hole_node->node_list.next, struct drm_mm_node,
node_list);
child = drm_mm_kmalloc(parent->mm, atomic);
if (unlikely(child == NULL))
return NULL;
INIT_LIST_HEAD(&child->free_stack);
child->size = size;
child->start = parent->start;
child->mm = parent->mm;
list_add_tail(&child->node_list, &parent->node_list);
INIT_LIST_HEAD(&child->free_stack);
parent->size -= size;
parent->start += size;
return child;
return next_node->start;
}
struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
unsigned long size,
unsigned alignment,
int atomic)
{
struct drm_mm_node *align_splitoff = NULL;
unsigned tmp = 0;
struct drm_mm_node *node;
struct drm_mm *mm = hole_node->mm;
unsigned long tmp = 0, wasted = 0;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
unsigned long hole_end = drm_mm_hole_node_end(hole_node);
BUG_ON(!hole_node->hole_follows);
node = drm_mm_kmalloc(mm, atomic);
if (unlikely(node == NULL))
return NULL;
if (alignment)
tmp = node->start % alignment;
tmp = hole_start % alignment;
if (tmp) {
align_splitoff =
drm_mm_split_at_start(node, alignment - tmp, atomic);
if (unlikely(align_splitoff == NULL))
return NULL;
}
if (!tmp) {
hole_node->hole_follows = 0;
list_del_init(&hole_node->hole_stack);
} else
wasted = alignment - tmp;
if (node->size == size) {
list_del_init(&node->free_stack);
node->free = 0;
node->start = hole_start + wasted;
node->size = size;
node->mm = mm;
INIT_LIST_HEAD(&node->hole_stack);
list_add(&node->node_list, &hole_node->node_list);
BUG_ON(node->start + node->size > hole_end);
if (node->start + node->size < hole_end) {
list_add(&node->hole_stack, &mm->hole_stack);
node->hole_follows = 1;
} else {
node = drm_mm_split_at_start(node, size, atomic);
node->hole_follows = 0;
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_generic);
struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *node,
struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
int atomic)
{
struct drm_mm_node *align_splitoff = NULL;
unsigned tmp = 0;
unsigned wasted = 0;
struct drm_mm_node *node;
struct drm_mm *mm = hole_node->mm;
unsigned long tmp = 0, wasted = 0;
unsigned long hole_start = drm_mm_hole_node_start(hole_node);
unsigned long hole_end = drm_mm_hole_node_end(hole_node);
if (node->start < start)
wasted += start - node->start;
BUG_ON(!hole_node->hole_follows);
node = drm_mm_kmalloc(mm, atomic);
if (unlikely(node == NULL))
return NULL;
if (hole_start < start)
wasted += start - hole_start;
if (alignment)
tmp = ((node->start + wasted) % alignment);
tmp = (hole_start + wasted) % alignment;
if (tmp)
wasted += alignment - tmp;
if (wasted) {
align_splitoff = drm_mm_split_at_start(node, wasted, atomic);
if (unlikely(align_splitoff == NULL))
return NULL;
if (!wasted) {
hole_node->hole_follows = 0;
list_del_init(&hole_node->hole_stack);
}
if (node->size == size) {
list_del_init(&node->free_stack);
node->free = 0;
node->start = hole_start + wasted;
node->size = size;
node->mm = mm;
INIT_LIST_HEAD(&node->hole_stack);
list_add(&node->node_list, &hole_node->node_list);
BUG_ON(node->start + node->size > hole_end);
BUG_ON(node->start + node->size > end);
if (node->start + node->size < hole_end) {
list_add(&node->hole_stack, &mm->hole_stack);
node->hole_follows = 1;
} else {
node = drm_mm_split_at_start(node, size, atomic);
node->hole_follows = 0;
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_range_generic);
@ -223,66 +220,41 @@ EXPORT_SYMBOL(drm_mm_get_block_range_generic);
* Otherwise add to the free stack.
*/
void drm_mm_put_block(struct drm_mm_node *cur)
void drm_mm_put_block(struct drm_mm_node *node)
{
struct drm_mm *mm = cur->mm;
struct list_head *cur_head = &cur->node_list;
struct list_head *root_head = &mm->node_list;
struct drm_mm_node *prev_node = NULL;
struct drm_mm_node *next_node;
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
int merged = 0;
BUG_ON(node->scanned_block || node->scanned_prev_free
|| node->scanned_next_free);
BUG_ON(cur->scanned_block || cur->scanned_prev_free
|| cur->scanned_next_free);
prev_node =
list_entry(node->node_list.prev, struct drm_mm_node, node_list);
if (cur_head->prev != root_head) {
prev_node =
list_entry(cur_head->prev, struct drm_mm_node, node_list);
if (prev_node->free) {
prev_node->size += cur->size;
merged = 1;
}
}
if (cur_head->next != root_head) {
next_node =
list_entry(cur_head->next, struct drm_mm_node, node_list);
if (next_node->free) {
if (merged) {
prev_node->size += next_node->size;
list_del(&next_node->node_list);
list_del(&next_node->free_stack);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&next_node->free_stack,
&mm->unused_nodes);
++mm->num_unused;
} else
kfree(next_node);
spin_unlock(&mm->unused_lock);
} else {
next_node->size += cur->size;
next_node->start = cur->start;
merged = 1;
}
}
}
if (!merged) {
cur->free = 1;
list_add(&cur->free_stack, &mm->free_stack);
} else {
list_del(&cur->node_list);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&cur->free_stack, &mm->unused_nodes);
++mm->num_unused;
} else
kfree(cur);
spin_unlock(&mm->unused_lock);
}
if (node->hole_follows) {
BUG_ON(drm_mm_hole_node_start(node)
== drm_mm_hole_node_end(node));
list_del(&node->hole_stack);
} else
BUG_ON(drm_mm_hole_node_start(node)
!= drm_mm_hole_node_end(node));
if (!prev_node->hole_follows) {
prev_node->hole_follows = 1;
list_add(&prev_node->hole_stack, &mm->hole_stack);
} else
list_move(&prev_node->hole_stack, &mm->hole_stack);
list_del(&node->node_list);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&node->node_list, &mm->unused_nodes);
++mm->num_unused;
} else
kfree(node);
spin_unlock(&mm->unused_lock);
}
EXPORT_SYMBOL(drm_mm_put_block);
static int check_free_hole(unsigned long start, unsigned long end,
@ -319,8 +291,10 @@ struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) {
if (!check_free_hole(entry->start, entry->start + entry->size,
list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
BUG_ON(!entry->hole_follows);
if (!check_free_hole(drm_mm_hole_node_start(entry),
drm_mm_hole_node_end(entry),
size, alignment))
continue;
@ -353,12 +327,13 @@ struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) {
unsigned long adj_start = entry->start < start ?
start : entry->start;
unsigned long adj_end = entry->start + entry->size > end ?
end : entry->start + entry->size;
list_for_each_entry(entry, &mm->hole_stack, hole_stack) {
unsigned long adj_start = drm_mm_hole_node_start(entry) < start ?
start : drm_mm_hole_node_start(entry);
unsigned long adj_end = drm_mm_hole_node_end(entry) > end ?
end : drm_mm_hole_node_end(entry);
BUG_ON(!entry->hole_follows);
if (!check_free_hole(adj_start, adj_end, size, alignment))
continue;
@ -430,70 +405,40 @@ EXPORT_SYMBOL(drm_mm_init_scan_with_range);
int drm_mm_scan_add_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct list_head *prev_free, *next_free;
struct drm_mm_node *prev_node, *next_node;
struct drm_mm_node *prev_node;
unsigned long hole_start, hole_end;
unsigned long adj_start;
unsigned long adj_end;
mm->scanned_blocks++;
prev_free = next_free = NULL;
BUG_ON(node->free);
BUG_ON(node->scanned_block);
node->scanned_block = 1;
node->free = 1;
if (node->node_list.prev != &mm->node_list) {
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
if (prev_node->free) {
list_del(&prev_node->node_list);
node->start = prev_node->start;
node->size += prev_node->size;
prev_node->scanned_prev_free = 1;
prev_free = &prev_node->free_stack;
}
}
if (node->node_list.next != &mm->node_list) {
next_node = list_entry(node->node_list.next, struct drm_mm_node,
node_list);
if (next_node->free) {
list_del(&next_node->node_list);
node->size += next_node->size;
next_node->scanned_next_free = 1;
next_free = &next_node->free_stack;
}
}
/* The free_stack list is not used for allocated objects, so these two
* pointers can be abused (as long as no allocations in this memory
* manager happens). */
node->free_stack.prev = prev_free;
node->free_stack.next = next_free;
node->scanned_preceeds_hole = prev_node->hole_follows;
prev_node->hole_follows = 1;
list_del(&node->node_list);
node->node_list.prev = &prev_node->node_list;
hole_start = drm_mm_hole_node_start(prev_node);
hole_end = drm_mm_hole_node_end(prev_node);
if (mm->scan_check_range) {
adj_start = node->start < mm->scan_start ?
mm->scan_start : node->start;
adj_end = node->start + node->size > mm->scan_end ?
mm->scan_end : node->start + node->size;
adj_start = hole_start < mm->scan_start ?
mm->scan_start : hole_start;
adj_end = hole_end > mm->scan_end ?
mm->scan_end : hole_end;
} else {
adj_start = node->start;
adj_end = node->start + node->size;
adj_start = hole_start;
adj_end = hole_end;
}
if (check_free_hole(adj_start , adj_end,
mm->scan_size, mm->scan_alignment)) {
mm->scan_hit_start = node->start;
mm->scan_hit_size = node->size;
mm->scan_hit_start = hole_start;
mm->scan_hit_size = hole_end;
return 1;
}
@ -519,39 +464,19 @@ EXPORT_SYMBOL(drm_mm_scan_add_block);
int drm_mm_scan_remove_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node, *next_node;
struct drm_mm_node *prev_node;
mm->scanned_blocks--;
BUG_ON(!node->scanned_block);
node->scanned_block = 0;
node->free = 0;
prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
free_stack);
next_node = list_entry(node->free_stack.next, struct drm_mm_node,
free_stack);
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
if (prev_node) {
BUG_ON(!prev_node->scanned_prev_free);
prev_node->scanned_prev_free = 0;
list_add_tail(&prev_node->node_list, &node->node_list);
node->start = prev_node->start + prev_node->size;
node->size -= prev_node->size;
}
if (next_node) {
BUG_ON(!next_node->scanned_next_free);
next_node->scanned_next_free = 0;
list_add(&next_node->node_list, &node->node_list);
node->size -= next_node->size;
}
INIT_LIST_HEAD(&node->free_stack);
prev_node->hole_follows = node->scanned_preceeds_hole;
INIT_LIST_HEAD(&node->node_list);
list_add(&node->node_list, &prev_node->node_list);
/* Only need to check for containement because start&size for the
* complete resulting free block (not just the desired part) is
@ -568,7 +493,7 @@ EXPORT_SYMBOL(drm_mm_scan_remove_block);
int drm_mm_clean(struct drm_mm * mm)
{
struct list_head *head = &mm->node_list;
struct list_head *head = &mm->head_node.node_list;
return (head->next->next == head);
}
@ -576,38 +501,40 @@ EXPORT_SYMBOL(drm_mm_clean);
int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
{
INIT_LIST_HEAD(&mm->node_list);
INIT_LIST_HEAD(&mm->free_stack);
INIT_LIST_HEAD(&mm->hole_stack);
INIT_LIST_HEAD(&mm->unused_nodes);
mm->num_unused = 0;
mm->scanned_blocks = 0;
spin_lock_init(&mm->unused_lock);
return drm_mm_create_tail_node(mm, start, size, 0);
/* Clever trick to avoid a special case in the free hole tracking. */
INIT_LIST_HEAD(&mm->head_node.node_list);
INIT_LIST_HEAD(&mm->head_node.hole_stack);
mm->head_node.hole_follows = 1;
mm->head_node.scanned_block = 0;
mm->head_node.scanned_prev_free = 0;
mm->head_node.scanned_next_free = 0;
mm->head_node.mm = mm;
mm->head_node.start = start + size;
mm->head_node.size = start - mm->head_node.start;
list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack);
return 0;
}
EXPORT_SYMBOL(drm_mm_init);
void drm_mm_takedown(struct drm_mm * mm)
{
struct list_head *bnode = mm->free_stack.next;
struct drm_mm_node *entry;
struct drm_mm_node *next;
struct drm_mm_node *entry, *next;
entry = list_entry(bnode, struct drm_mm_node, free_stack);
if (entry->node_list.next != &mm->node_list ||
entry->free_stack.next != &mm->free_stack) {
if (!list_empty(&mm->head_node.node_list)) {
DRM_ERROR("Memory manager not clean. Delaying takedown\n");
return;
}
list_del(&entry->free_stack);
list_del(&entry->node_list);
kfree(entry);
spin_lock(&mm->unused_lock);
list_for_each_entry_safe(entry, next, &mm->unused_nodes, free_stack) {
list_del(&entry->free_stack);
list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
list_del(&entry->node_list);
kfree(entry);
--mm->num_unused;
}
@ -620,19 +547,37 @@ EXPORT_SYMBOL(drm_mm_takedown);
void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
{
struct drm_mm_node *entry;
int total_used = 0, total_free = 0, total = 0;
unsigned long total_used = 0, total_free = 0, total = 0;
unsigned long hole_start, hole_end, hole_size;
list_for_each_entry(entry, &mm->node_list, node_list) {
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8ld: %s\n",
hole_start = drm_mm_hole_node_start(&mm->head_node);
hole_end = drm_mm_hole_node_end(&mm->head_node);
hole_size = hole_end - hole_start;
if (hole_size)
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
prefix, hole_start, hole_end,
hole_size);
total_free += hole_size;
drm_mm_for_each_node(entry, mm) {
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
prefix, entry->start, entry->start + entry->size,
entry->size, entry->free ? "free" : "used");
total += entry->size;
if (entry->free)
total_free += entry->size;
else
total_used += entry->size;
entry->size);
total_used += entry->size;
if (entry->hole_follows) {
hole_start = drm_mm_hole_node_start(entry);
hole_end = drm_mm_hole_node_end(entry);
hole_size = hole_end - hole_start;
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
prefix, hole_start, hole_end,
hole_size);
total_free += hole_size;
}
}
printk(KERN_DEBUG "%s total: %d, used %d free %d\n", prefix, total,
total = total_free + total_used;
printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
total_used, total_free);
}
EXPORT_SYMBOL(drm_mm_debug_table);
@ -641,17 +586,34 @@ EXPORT_SYMBOL(drm_mm_debug_table);
int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
{
struct drm_mm_node *entry;
int total_used = 0, total_free = 0, total = 0;
unsigned long total_used = 0, total_free = 0, total = 0;
unsigned long hole_start, hole_end, hole_size;
list_for_each_entry(entry, &mm->node_list, node_list) {
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
total += entry->size;
if (entry->free)
total_free += entry->size;
else
total_used += entry->size;
hole_start = drm_mm_hole_node_start(&mm->head_node);
hole_end = drm_mm_hole_node_end(&mm->head_node);
hole_size = hole_end - hole_start;
if (hole_size)
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
hole_start, hole_end, hole_size);
total_free += hole_size;
drm_mm_for_each_node(entry, mm) {
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
entry->start, entry->start + entry->size,
entry->size);
total_used += entry->size;
if (entry->hole_follows) {
hole_start = drm_mm_hole_node_start(&mm->head_node);
hole_end = drm_mm_hole_node_end(&mm->head_node);
hole_size = hole_end - hole_start;
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
hole_start, hole_end, hole_size);
total_free += hole_size;
}
}
seq_printf(m, "total: %d, used %d free %d\n", total, total_used, total_free);
total = total_free + total_used;
seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
return 0;
}
EXPORT_SYMBOL(drm_mm_dump_table);

21
include/drm/drm_mm.h
View File

@ -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)
*/