mmc: s3c6410: enable ADMA feature in 6410 sdhci controller
[safe/jmp/linux-2.6] / kernel / rcutree_plugin.h
index f9bc83a..0e4f420 100644 (file)
 
 #include <linux/delay.h>
 
+/*
+ * Check the RCU kernel configuration parameters and print informative
+ * messages about anything out of the ordinary.  If you like #ifdef, you
+ * will love this function.
+ */
+static void __init rcu_bootup_announce_oddness(void)
+{
+#ifdef CONFIG_RCU_TRACE
+       printk(KERN_INFO "\tRCU debugfs-based tracing is enabled.\n");
+#endif
+#if (defined(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 64) || (!defined(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 32)
+       printk(KERN_INFO "\tCONFIG_RCU_FANOUT set to non-default value of %d\n",
+              CONFIG_RCU_FANOUT);
+#endif
+#ifdef CONFIG_RCU_FANOUT_EXACT
+       printk(KERN_INFO "\tHierarchical RCU autobalancing is disabled.\n");
+#endif
+#ifdef CONFIG_RCU_FAST_NO_HZ
+       printk(KERN_INFO
+              "\tRCU dyntick-idle grace-period acceleration is enabled.\n");
+#endif
+#ifdef CONFIG_PROVE_RCU
+       printk(KERN_INFO "\tRCU lockdep checking is enabled.\n");
+#endif
+#ifdef CONFIG_RCU_TORTURE_TEST_RUNNABLE
+       printk(KERN_INFO "\tRCU torture testing starts during boot.\n");
+#endif
+#ifndef CONFIG_RCU_CPU_STALL_DETECTOR
+       printk(KERN_INFO
+              "\tRCU-based detection of stalled CPUs is disabled.\n");
+#endif
+#ifndef CONFIG_RCU_CPU_STALL_VERBOSE
+       printk(KERN_INFO "\tVerbose stalled-CPUs detection is disabled.\n");
+#endif
+#if NUM_RCU_LVL_4 != 0
+       printk(KERN_INFO "\tExperimental four-level hierarchy is enabled.\n");
+#endif
+}
+
 #ifdef CONFIG_TREE_PREEMPT_RCU
 
 struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt_state);
@@ -38,8 +77,8 @@ static int rcu_preempted_readers_exp(struct rcu_node *rnp);
  */
 static void __init rcu_bootup_announce(void)
 {
-       printk(KERN_INFO
-              "Experimental preemptable hierarchical RCU implementation.\n");
+       printk(KERN_INFO "Preemptable hierarchical RCU implementation.\n");
+       rcu_bootup_announce_oddness();
 }
 
 /*
@@ -518,11 +557,13 @@ void synchronize_rcu(void)
        if (!rcu_scheduler_active)
                return;
 
+       init_rcu_head_on_stack(&rcu.head);
        init_completion(&rcu.completion);
        /* Will wake me after RCU finished. */
        call_rcu(&rcu.head, wakeme_after_rcu);
        /* Wait for it. */
        wait_for_completion(&rcu.completion);
+       destroy_rcu_head_on_stack(&rcu.head);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
@@ -757,6 +798,7 @@ void exit_rcu(void)
 static void __init rcu_bootup_announce(void)
 {
        printk(KERN_INFO "Hierarchical RCU implementation.\n");
+       rcu_bootup_announce_oddness();
 }
 
 /*
@@ -1011,6 +1053,8 @@ static DEFINE_PER_CPU(unsigned long, rcu_dyntick_holdoff);
 int rcu_needs_cpu(int cpu)
 {
        int c = 0;
+       int snap;
+       int snap_nmi;
        int thatcpu;
 
        /* Check for being in the holdoff period. */
@@ -1018,12 +1062,18 @@ int rcu_needs_cpu(int cpu)
                return rcu_needs_cpu_quick_check(cpu);
 
        /* Don't bother unless we are the last non-dyntick-idle CPU. */
-       for_each_cpu_not(thatcpu, nohz_cpu_mask)
-               if (cpu_online(thatcpu) && thatcpu != cpu) {
+       for_each_online_cpu(thatcpu) {
+               if (thatcpu == cpu)
+                       continue;
+               snap = per_cpu(rcu_dynticks, thatcpu).dynticks;
+               snap_nmi = per_cpu(rcu_dynticks, thatcpu).dynticks_nmi;
+               smp_mb(); /* Order sampling of snap with end of grace period. */
+               if (((snap & 0x1) != 0) || ((snap_nmi & 0x1) != 0)) {
                        per_cpu(rcu_dyntick_drain, cpu) = 0;
                        per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
                        return rcu_needs_cpu_quick_check(cpu);
                }
+       }
 
        /* Check and update the rcu_dyntick_drain sequencing. */
        if (per_cpu(rcu_dyntick_drain, cpu) <= 0) {