Commit 0839ade9 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

srcu: Move ->lock initialization after srcu_usage allocation 



Currently, both __init_srcu_struct() in CONFIG_DEBUG_LOCK_ALLOC=y kernels
and init_srcu_struct() in CONFIG_DEBUG_LOCK_ALLOC=n kernel initialize
the srcu_struct structure's ->lock before the srcu_usage structure has
been allocated.  This of course prevents the ->lock from being moved
to the srcu_usage structure, so this commit moves the initialization
into the init_srcu_struct_fields() after the srcu_usage structure has
been allocated.

Cc: Christoph Hellwig <hch@lst.de>
Tested-by: default avatarSachin Sant <sachinp@linux.ibm.com>
Tested-by: default avatar"Zhang, Qiang1" <qiang1.zhang@intel.com>
Tested-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 574dc1a7

kernel/rcu/srcutree.c

+2 −2
Original line number Diff line number Diff line
@@ -240,6 +240,8 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) 
		ssp->srcu_sup = kzalloc(sizeof(*ssp->srcu_sup), GFP_KERNEL);

	if (!ssp->srcu_sup)

		return -ENOMEM;

	if (!is_static)

		spin_lock_init(&ACCESS_PRIVATE(ssp, lock));

	ssp->srcu_sup->srcu_size_state = SRCU_SIZE_SMALL;

	ssp->srcu_sup->node = NULL;

	mutex_init(&ssp->srcu_sup->srcu_cb_mutex);
@@ -285,7 +287,6 @@ int __init_srcu_struct(struct srcu_struct *ssp, const char *name, 
	/* Don't re-initialize a lock while it is held. */

	debug_check_no_locks_freed((void *)ssp, sizeof(*ssp));

	lockdep_init_map(&ssp->dep_map, name, key, 0);

	spin_lock_init(&ACCESS_PRIVATE(ssp, lock));

	return init_srcu_struct_fields(ssp, false);

}

EXPORT_SYMBOL_GPL(__init_srcu_struct);
@@ -302,7 +303,6 @@ EXPORT_SYMBOL_GPL(__init_srcu_struct); 
 */

int init_srcu_struct(struct srcu_struct *ssp)

{

	spin_lock_init(&ACCESS_PRIVATE(ssp, lock));

	return init_srcu_struct_fields(ssp, false);

}

EXPORT_SYMBOL_GPL(init_srcu_struct);