block/cfq: cache rightmost rb_node (f0f1a45f) · Commits · 戴 / test

block/cfq-iosched.c

+14 −5

Original line number	Original line	Diff line number	Diff line
	@@ -94,11 +94,13 @@ struct cfq_ttime {
	*/		*/
	struct cfq_rb_root {		struct cfq_rb_root {
	struct rb_root_cached rb;		struct rb_root_cached rb;
			struct rb_node *rb_rightmost;
	unsigned count;		unsigned count;
	u64 min_vdisktime;		u64 min_vdisktime;
	struct cfq_ttime ttime;		struct cfq_ttime ttime;
	};		};
	#define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT_CACHED, \		#define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT_CACHED, \
			.rb_rightmost = NULL, \
	.ttime = {.last_end_request = ktime_get_ns(),},}		.ttime = {.last_end_request = ktime_get_ns(),},}

	/*		/*
	@@ -1180,6 +1182,9 @@ static struct cfq_group cfq_rb_first_group(struct cfq_rb_root root)

	static void cfq_rb_erase(struct rb_node n, struct cfq_rb_root root)		static void cfq_rb_erase(struct rb_node n, struct cfq_rb_root root)
	{		{
			if (root->rb_rightmost == n)
			root->rb_rightmost = rb_prev(n);

	rb_erase_cached(n, &root->rb);		rb_erase_cached(n, &root->rb);
	RB_CLEAR_NODE(n);		RB_CLEAR_NODE(n);

	@@ -1236,20 +1241,24 @@ __cfq_group_service_tree_add(struct cfq_rb_root st, struct cfq_group cfqg)
	struct rb_node *parent = NULL;		struct rb_node *parent = NULL;
	struct cfq_group *__cfqg;		struct cfq_group *__cfqg;
	s64 key = cfqg_key(st, cfqg);		s64 key = cfqg_key(st, cfqg);
	bool leftmost = true;		bool leftmost = true, rightmost = true;

	while (*node != NULL) {		while (*node != NULL) {
	parent = *node;		parent = *node;
	__cfqg = rb_entry_cfqg(parent);		__cfqg = rb_entry_cfqg(parent);

	if (key < cfqg_key(st, __cfqg))		if (key < cfqg_key(st, __cfqg)) {
	node = &parent->rb_left;		node = &parent->rb_left;
	else {		rightmost = false;
			} else {
	node = &parent->rb_right;		node = &parent->rb_right;
	leftmost = false;		leftmost = false;
	}		}
	}		}

			if (rightmost)
			st->rb_rightmost = &cfqg->rb_node;

	rb_link_node(&cfqg->rb_node, parent, node);		rb_link_node(&cfqg->rb_node, parent, node);
	rb_insert_color_cached(&cfqg->rb_node, &st->rb, leftmost);		rb_insert_color_cached(&cfqg->rb_node, &st->rb, leftmost);
	}		}
	@@ -1352,7 +1361,7 @@ cfq_group_notify_queue_add(struct cfq_data cfqd, struct cfq_group cfqg)
	* so that groups get lesser vtime based on their weights, so that		* so that groups get lesser vtime based on their weights, so that
	* if group does not loose all if it was not continuously backlogged.		* if group does not loose all if it was not continuously backlogged.
	*/		*/
	n = rb_last(&st->rb.rb_root);		n = st->rb_rightmost;
	if (n) {		if (n) {
	__cfqg = rb_entry_cfqg(n);		__cfqg = rb_entry_cfqg(n);
	cfqg->vdisktime = __cfqg->vdisktime +		cfqg->vdisktime = __cfqg->vdisktime +
	@@ -2201,7 +2210,7 @@ static void cfq_service_tree_add(struct cfq_data cfqd, struct cfq_queue cfqq,
	st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));		st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));
	if (cfq_class_idle(cfqq)) {		if (cfq_class_idle(cfqq)) {
	rb_key = CFQ_IDLE_DELAY;		rb_key = CFQ_IDLE_DELAY;
	parent = rb_last(&st->rb.rb_root);		parent = st->rb_rightmost;
	if (parent && parent != &cfqq->rb_node) {		if (parent && parent != &cfqq->rb_node) {
	__cfqq = rb_entry(parent, struct cfq_queue, rb_node);		__cfqq = rb_entry(parent, struct cfq_queue, rb_node);
	rb_key += __cfqq->rb_key;		rb_key += __cfqq->rb_key;

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