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Commit 83c2c735 authored by Paul E. McKenney's avatar Paul E. McKenney
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rcu: Stop silencing lockdep false positive for expedited grace periods 

This reverts commit af859bea (rcu: Silence lockdep false positive
for expedited grace periods).  Because synchronize_rcu_expedited()
no longer invokes synchronize_sched_expedited(), ->exp_funnel_mutex
acquisition is no longer nested, so the false positive no longer happens.
This commit therefore removes the extra lockdep data structures, as they
are no longer needed.
parent 6587a23b

kernel/rcu/tree.c

+2 −15
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ MODULE_ALIAS("rcutree"); 
static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];

static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];

static struct lock_class_key rcu_exp_class[RCU_NUM_LVLS];

static struct lock_class_key rcu_exp_sched_class[RCU_NUM_LVLS];



/*

 * In order to export the rcu_state name to the tracing tools, it
@@ -4095,7 +4094,6 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf) 
static void __init

rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)

{

	static struct lock_class_key rcu_exp_sched_rdp_class;

	unsigned long flags;

	struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);

	struct rcu_node *rnp = rcu_get_root(rsp);
@@ -4111,10 +4109,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) 
	mutex_init(&rdp->exp_funnel_mutex);

	rcu_boot_init_nocb_percpu_data(rdp);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

	if (rsp == &rcu_sched_state)

		lockdep_set_class_and_name(&rdp->exp_funnel_mutex,

					   &rcu_exp_sched_rdp_class,

					   "rcu_data_exp_sched");

}



/*
@@ -4340,7 +4334,6 @@ static void __init rcu_init_one(struct rcu_state *rsp, 
	static const char * const buf[] = RCU_NODE_NAME_INIT;

	static const char * const fqs[] = RCU_FQS_NAME_INIT;

	static const char * const exp[] = RCU_EXP_NAME_INIT;

	static const char * const exp_sched[] = RCU_EXP_SCHED_NAME_INIT;

	static u8 fl_mask = 0x1;



	int levelcnt[RCU_NUM_LVLS];		/* # nodes in each level. */
@@ -4400,13 +4393,7 @@ static void __init rcu_init_one(struct rcu_state *rsp, 
			INIT_LIST_HEAD(&rnp->blkd_tasks);

			rcu_init_one_nocb(rnp);

			mutex_init(&rnp->exp_funnel_mutex);

			if (rsp == &rcu_sched_state)

				lockdep_set_class_and_name(

					&rnp->exp_funnel_mutex,

					&rcu_exp_sched_class[i], exp_sched[i]);

			else

				lockdep_set_class_and_name(

					&rnp->exp_funnel_mutex,

			lockdep_set_class_and_name(&rnp->exp_funnel_mutex,

						   &rcu_exp_class[i], exp[i]);

		}

	}

kernel/rcu/tree.h

+0 −8
Original line number Diff line number Diff line
@@ -70,8 +70,6 @@ 
#  define RCU_NODE_NAME_INIT  { "rcu_node_0" }

#  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0" }

#  define RCU_EXP_NAME_INIT   { "rcu_node_exp_0" }

#  define RCU_EXP_SCHED_NAME_INIT \

			      { "rcu_node_exp_sched_0" }

#elif NR_CPUS <= RCU_FANOUT_2

#  define RCU_NUM_LVLS	      2

#  define NUM_RCU_LVL_0	      1
@@ -81,8 +79,6 @@ 
#  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1" }

#  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1" }

#  define RCU_EXP_NAME_INIT   { "rcu_node_exp_0", "rcu_node_exp_1" }

#  define RCU_EXP_SCHED_NAME_INIT \

			      { "rcu_node_exp_sched_0", "rcu_node_exp_sched_1" }

#elif NR_CPUS <= RCU_FANOUT_3

#  define RCU_NUM_LVLS	      3

#  define NUM_RCU_LVL_0	      1
@@ -93,8 +89,6 @@ 
#  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1", "rcu_node_2" }

#  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2" }

#  define RCU_EXP_NAME_INIT   { "rcu_node_exp_0", "rcu_node_exp_1", "rcu_node_exp_2" }

#  define RCU_EXP_SCHED_NAME_INIT \

			      { "rcu_node_exp_sched_0", "rcu_node_exp_sched_1", "rcu_node_exp_sched_2" }

#elif NR_CPUS <= RCU_FANOUT_4

#  define RCU_NUM_LVLS	      4

#  define NUM_RCU_LVL_0	      1
@@ -106,8 +100,6 @@ 
#  define RCU_NODE_NAME_INIT  { "rcu_node_0", "rcu_node_1", "rcu_node_2", "rcu_node_3" }

#  define RCU_FQS_NAME_INIT   { "rcu_node_fqs_0", "rcu_node_fqs_1", "rcu_node_fqs_2", "rcu_node_fqs_3" }

#  define RCU_EXP_NAME_INIT   { "rcu_node_exp_0", "rcu_node_exp_1", "rcu_node_exp_2", "rcu_node_exp_3" }

#  define RCU_EXP_SCHED_NAME_INIT \

			      { "rcu_node_exp_sched_0", "rcu_node_exp_sched_1", "rcu_node_exp_sched_2", "rcu_node_exp_sched_3" }

#else

# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"

#endif /* #if (NR_CPUS) <= RCU_FANOUT_1 */