rcu: Stop silencing lockdep false positive for expedited grace periods

This reverts commit af859beaaba4 (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.

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a42168911941eb501fd67664155373d9ed41acf4..15b19baaade5971fc54dd717e81c6f6f2e0e8ad2 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -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. */
@@ -4400,14 +4393,8 @@ 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,
-                                       &rcu_exp_class[i], exp[i]);
+                       lockdep_set_class_and_name(&rnp->exp_funnel_mutex,
+                                                  &rcu_exp_class[i], exp[i]);
                }
        }
 

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 1b969cef8fe4f5d3c04251a9ffe63ed17058baad..6f3b63b68886b4c56ae7c5edf615ad5440cd49c5 100644 (file)
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -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 */