Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f1e8c671 authored by Chris Wilson's avatar Chris Wilson Committed by Gustavo Padovan
Browse files

dma-buf/sw-sync: Use an rbtree to sort fences in the timeline 



Reduce the list iteration when incrementing the timeline by storing the
fences in increasing order.

v2: Prevent spinlock recursion on free during create
v3: Fixup rebase conflict inside comments that escaped the compiler.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Reviewed-by: default avatarSean Paul <seanpaul@chromium.org>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629211253.22766-1-chris@chris-wilson.co.uk
parent d3862e44

drivers/dma-buf/sw_sync.c

+43 −6
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ static struct sync_timeline *sync_timeline_create(const char *name) 
	obj->context = dma_fence_context_alloc(1);

	strlcpy(obj->name, name, sizeof(obj->name));



	obj->pt_tree = RB_ROOT;

	INIT_LIST_HEAD(&obj->pt_list);

	spin_lock_init(&obj->lock);
@@ -142,9 +143,13 @@ static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc) 


	obj->value += inc;



	list_for_each_entry_safe(pt, next, &obj->pt_list, link)

		if (dma_fence_is_signaled_locked(&pt->base))

	list_for_each_entry_safe(pt, next, &obj->pt_list, link) {

		if (!dma_fence_is_signaled_locked(&pt->base))

			break;



		list_del_init(&pt->link);

		rb_erase(&pt->node, &obj->pt_tree);

	}



	spin_unlock_irq(&obj->lock);

}
@@ -174,8 +179,38 @@ static struct sync_pt *sync_pt_create(struct sync_timeline *obj, 
	INIT_LIST_HEAD(&pt->link);



	spin_lock_irq(&obj->lock);

	if (!dma_fence_is_signaled_locked(&pt->base))

		list_add_tail(&pt->link, &obj->pt_list);

	if (!dma_fence_is_signaled_locked(&pt->base)) {

		struct rb_node **p = &obj->pt_tree.rb_node;

		struct rb_node *parent = NULL;



		while (*p) {

			struct sync_pt *other;

			int cmp;



			parent = *p;

			other = rb_entry(parent, typeof(*pt), node);

			cmp = value - other->base.seqno;

			if (cmp > 0) {

				p = &parent->rb_right;

			} else if (cmp < 0) {

				p = &parent->rb_left;

			} else {

				if (dma_fence_get_rcu(&other->base)) {

					dma_fence_put(&pt->base);

					pt = other;

					goto unlock;

				}

				p = &parent->rb_left;

			}

		}

		rb_link_node(&pt->node, parent, p);

		rb_insert_color(&pt->node, &obj->pt_tree);



		parent = rb_next(&pt->node);

		list_add_tail(&pt->link,

			      parent ? &rb_entry(parent, typeof(*pt), node)->link : &obj->pt_list);

	}

unlock:

	spin_unlock_irq(&obj->lock);



	return pt;
@@ -202,8 +237,10 @@ static void timeline_fence_release(struct dma_fence *fence) 
		unsigned long flags;



		spin_lock_irqsave(fence->lock, flags);

		if (!list_empty(&pt->link))

		if (!list_empty(&pt->link)) {

			list_del(&pt->link);

			rb_erase(&pt->node, &parent->pt_tree);

		}

		spin_unlock_irqrestore(fence->lock, flags);

	}

drivers/dma-buf/sync_debug.h

+5 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#define _LINUX_SYNC_H



#include <linux/list.h>

#include <linux/rbtree.h>

#include <linux/spinlock.h>

#include <linux/dma-fence.h>
@@ -25,6 +26,7 @@ 
 * @kref:		reference count on fence.

 * @name:		name of the sync_timeline. Useful for debugging

 * @lock:		lock protecting @pt_list and @value

 * @pt_tree:		rbtree of active (unsignaled/errored) sync_pts

 * @pt_list:		list of active (unsignaled/errored) sync_pts

 * @sync_timeline_list:	membership in global sync_timeline_list

 */
@@ -36,6 +38,7 @@ struct sync_timeline { 
	u64			context;

	int			value;



	struct rb_root		pt_tree;

	struct list_head	pt_list;

	spinlock_t		lock;
@@ -51,10 +54,12 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence) 
 * struct sync_pt - sync_pt object

 * @base: base fence object

 * @link: link on the sync timeline's list

 * @node: node in the sync timeline's tree

 */

struct sync_pt {

	struct dma_fence base;

	struct list_head link;

	struct rb_node node;

};



#ifdef CONFIG_SW_SYNC