rcu: Move TINY_PREEMPT_RCU away from raw_local_irq_save()

The use of raw_local_irq_save() is unnecessary, given that local_irq_save()
really does disable interrupts.  Also, it appears to interfere with lockdep.
Therefore, this commit moves to local_irq_save().

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>

diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index 918fd1e8509c9d5589d9ff75d0f63bca0b27cc32..3d0190282204308005f1867abe6d53125787e1b0 100644 (file)
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -278,7 +278,7 @@ static int rcu_boost(void)
            rcu_preempt_ctrlblk.exp_tasks == NULL)
                return 0;  /* Nothing to boost. */
 
-       raw_local_irq_save(flags);
+       local_irq_save(flags);
 
        /*
         * Recheck with irqs disabled: all tasks in need of boosting
@@ -287,7 +287,7 @@ static int rcu_boost(void)
         */
        if (rcu_preempt_ctrlblk.boost_tasks == NULL &&
            rcu_preempt_ctrlblk.exp_tasks == NULL) {
-               raw_local_irq_restore(flags);
+               local_irq_restore(flags);
                return 0;
        }
 
@@ -317,7 +317,7 @@ static int rcu_boost(void)
        t = container_of(tb, struct task_struct, rcu_node_entry);
        rt_mutex_init_proxy_locked(&mtx, t);
        t->rcu_boost_mutex = &mtx;
-       raw_local_irq_restore(flags);
+       local_irq_restore(flags);
        rt_mutex_lock(&mtx);
        rt_mutex_unlock(&mtx);  /* Keep lockdep happy. */
 
@@ -991,9 +991,9 @@ static void rcu_trace_sub_qlen(struct rcu_ctrlblk *rcp, int n)
 {
        unsigned long flags;
 
-       raw_local_irq_save(flags);
+       local_irq_save(flags);
        rcp->qlen -= n;
-       raw_local_irq_restore(flags);
+       local_irq_restore(flags);
 }
 
 /*