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Commit ef681026 authored by Ming Lei's avatar Ming Lei Committed by Peter Zijlstra
Browse files

lockdep: Implement lockdep_count_*ward_deps by BFS 



Implement lockdep_count_{for,back}ward using BFS.

Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1246201486-7308-8-git-send-email-tom.leiming@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 24208ca7

kernel/lockdep.c

+25 −27
Original line number Diff line number Diff line
@@ -1115,61 +1115,59 @@ static noinline int print_bfs_bug(int ret) 
	return 0;

}



unsigned long __lockdep_count_forward_deps(struct lock_class *class,

					   unsigned int depth)

static int noop_count(struct lock_list *entry, void *data)

{

	struct lock_list *entry;

	unsigned long ret = 1;



	if (lockdep_dependency_visit(class, depth))

	(*(unsigned long *)data)++;

	return 0;

}



	/*

	 * Recurse this class's dependency list:

	 */

	list_for_each_entry(entry, &class->locks_after, entry)

		ret += __lockdep_count_forward_deps(entry->class, depth + 1);

unsigned long __lockdep_count_forward_deps(struct lock_list *this)

{

	unsigned long  count = 0;

	struct lock_list *uninitialized_var(target_entry);



	return ret;

}

	__bfs_forwards(this, (void *)&count, noop_count, &target_entry);



	return count;

}

unsigned long lockdep_count_forward_deps(struct lock_class *class)

{

	unsigned long ret, flags;

	struct lock_list this;



	this.parent = NULL;

	this.class = class;



	local_irq_save(flags);

	__raw_spin_lock(&lockdep_lock);

	ret = __lockdep_count_forward_deps(class, 0);

	ret = __lockdep_count_forward_deps(&this);

	__raw_spin_unlock(&lockdep_lock);

	local_irq_restore(flags);



	return ret;

}



unsigned long __lockdep_count_backward_deps(struct lock_class *class,

					    unsigned int depth)

unsigned long __lockdep_count_backward_deps(struct lock_list *this)

{

	struct lock_list *entry;

	unsigned long ret = 1;

	unsigned long  count = 0;

	struct lock_list *uninitialized_var(target_entry);



	if (lockdep_dependency_visit(class, depth))

		return 0;

	/*

	 * Recurse this class's dependency list:

	 */

	list_for_each_entry(entry, &class->locks_before, entry)

		ret += __lockdep_count_backward_deps(entry->class, depth + 1);

	__bfs_backwards(this, (void *)&count, noop_count, &target_entry);



	return ret;

	return count;

}



unsigned long lockdep_count_backward_deps(struct lock_class *class)

{

	unsigned long ret, flags;

	struct lock_list this;



	this.parent = NULL;

	this.class = class;



	local_irq_save(flags);

	__raw_spin_lock(&lockdep_lock);

	ret = __lockdep_count_backward_deps(class, 0);

	ret = __lockdep_count_backward_deps(&this);

	__raw_spin_unlock(&lockdep_lock);

	local_irq_restore(flags);