1 files changed, 53 insertions, 28 deletions

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 3db5a375d8dd..63098a59216e 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -53,38 +53,37 @@ static char __initdata nocb_buf[NR_CPUS * 5];
 static void __init rcu_bootup_announce_oddness(void)
 {
 #ifdef CONFIG_RCU_TRACE
-        printk(KERN_INFO "\tRCU debugfs-based tracing is enabled.\n");
+        pr_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",
+        pr_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");
+        pr_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");
+        pr_info("\tRCU dyntick-idle grace-period acceleration is enabled.\n");
 #endif
 #ifdef CONFIG_PROVE_RCU
-        printk(KERN_INFO "\tRCU lockdep checking is enabled.\n");
+        pr_info("\tRCU lockdep checking is enabled.\n");
 #endif
 #ifdef CONFIG_RCU_TORTURE_TEST_RUNNABLE
-        printk(KERN_INFO "\tRCU torture testing starts during boot.\n");
+        pr_info("\tRCU torture testing starts during boot.\n");
 #endif
 #if defined(CONFIG_TREE_PREEMPT_RCU) && !defined(CONFIG_RCU_CPU_STALL_VERBOSE)
-        printk(KERN_INFO "\tDump stacks of tasks blocking RCU-preempt GP.\n");
+        pr_info("\tDump stacks of tasks blocking RCU-preempt GP.\n");
 #endif
 #if defined(CONFIG_RCU_CPU_STALL_INFO)
-        printk(KERN_INFO "\tAdditional per-CPU info printed with stalls.\n");
+        pr_info("\tAdditional per-CPU info printed with stalls.\n");
 #endif
 #if NUM_RCU_LVL_4 != 0
-        printk(KERN_INFO "\tFour-level hierarchy is enabled.\n");
+        pr_info("\tFour-level hierarchy is enabled.\n");
 #endif
         if (rcu_fanout_leaf != CONFIG_RCU_FANOUT_LEAF)
-                printk(KERN_INFO "\tExperimental boot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf);
+                pr_info("\tBoot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf);
         if (nr_cpu_ids != NR_CPUS)
-                printk(KERN_INFO "\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
+                pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
 #ifdef CONFIG_RCU_NOCB_CPU
 #ifndef CONFIG_RCU_NOCB_CPU_NONE
         if (!have_rcu_nocb_mask) {
@@ -92,19 +91,19 @@ static void __init rcu_bootup_announce_oddness(void)
                 have_rcu_nocb_mask = true;
         }
 #ifdef CONFIG_RCU_NOCB_CPU_ZERO
-        pr_info("\tExperimental no-CBs CPU 0\n");
+        pr_info("\tOffload RCU callbacks from CPU 0\n");
         cpumask_set_cpu(0, rcu_nocb_mask);
 #endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */
 #ifdef CONFIG_RCU_NOCB_CPU_ALL
-        pr_info("\tExperimental no-CBs for all CPUs\n");
+        pr_info("\tOffload RCU callbacks from all CPUs\n");
         cpumask_setall(rcu_nocb_mask);
 #endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */
 #endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */
         if (have_rcu_nocb_mask) {
                 cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask);
-                pr_info("\tExperimental no-CBs CPUs: %s.\n", nocb_buf);
+                pr_info("\tOffload RCU callbacks from CPUs: %s.\n", nocb_buf);
                 if (rcu_nocb_poll)
-                        pr_info("\tExperimental polled no-CBs CPUs.\n");
+                        pr_info("\tPoll for callbacks from no-CBs CPUs.\n");
         }
 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */
 }
@@ -123,7 +122,7 @@ static int rcu_preempted_readers_exp(struct rcu_node *rnp);
  */
 static void __init rcu_bootup_announce(void)
 {
-        printk(KERN_INFO "Preemptible hierarchical RCU implementation.\n");
+        pr_info("Preemptible hierarchical RCU implementation.\n");
         rcu_bootup_announce_oddness();
 }
 
@@ -490,13 +489,13 @@ static void rcu_print_detail_task_stall(struct rcu_state *rsp)
 
 static void rcu_print_task_stall_begin(struct rcu_node *rnp)
 {
-        printk(KERN_ERR "\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
+        pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):",
                rnp->level, rnp->grplo, rnp->grphi);
 }
 
 static void rcu_print_task_stall_end(void)
 {
-        printk(KERN_CONT "\n");
+        pr_cont("\n");
 }
 
 #else /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
@@ -526,7 +525,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp)
         t = list_entry(rnp->gp_tasks,
                        struct task_struct, rcu_node_entry);
         list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) {
-                printk(KERN_CONT " P%d", t->pid);
+                pr_cont(" P%d", t->pid);
                 ndetected++;
         }
         rcu_print_task_stall_end();
@@ -933,6 +932,24 @@ static void __init __rcu_init_preempt(void)
         rcu_init_one(&rcu_preempt_state, &rcu_preempt_data);
 }
 
+/*
+ * Check for a task exiting while in a preemptible-RCU read-side
+ * critical section, clean up if so.  No need to issue warnings,
+ * as debug_check_no_locks_held() already does this if lockdep
+ * is enabled.
+ */
+void exit_rcu(void)
+{
+        struct task_struct *t = current;
+
+        if (likely(list_empty(&current->rcu_node_entry)))
+                return;
+        t->rcu_read_lock_nesting = 1;
+        barrier();
+        t->rcu_read_unlock_special = RCU_READ_UNLOCK_BLOCKED;
+        __rcu_read_unlock();
+}
+
 #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
 static struct rcu_state *rcu_state = &rcu_sched_state;
@@ -942,7 +959,7 @@ static struct rcu_state *rcu_state = &rcu_sched_state;
  */
 static void __init rcu_bootup_announce(void)
 {
-        printk(KERN_INFO "Hierarchical RCU implementation.\n");
+        pr_info("Hierarchical RCU implementation.\n");
         rcu_bootup_announce_oddness();
 }
 
@@ -1101,6 +1118,14 @@ static void __init __rcu_init_preempt(void)
 {
 }
 
+/*
+ * Because preemptible RCU does not exist, tasks cannot possibly exit
+ * while in preemptible RCU read-side critical sections.
+ */
+void exit_rcu(void)
+{
+}
+
 #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
 
 #ifdef CONFIG_RCU_BOOST
@@ -1629,7 +1654,7 @@ static bool rcu_try_advance_all_cbs(void)
                  */
                 if (rdp->completed != rnp->completed &&
                     rdp->nxttail[RCU_DONE_TAIL] != rdp->nxttail[RCU_NEXT_TAIL])
-                        rcu_process_gp_end(rsp, rdp);
+                        note_gp_changes(rsp, rdp);
 
                 if (cpu_has_callbacks_ready_to_invoke(rdp))
                         cbs_ready = true;
@@ -1883,7 +1908,7 @@ static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
 /* Initiate the stall-info list. */
 static void print_cpu_stall_info_begin(void)
 {
-        printk(KERN_CONT "\n");
+        pr_cont("\n");
 }
 
 /*
@@ -1914,7 +1939,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
                 ticks_value = rsp->gpnum - rdp->gpnum;
         }
         print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
-        printk(KERN_ERR "\t%d: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u %s\n",
+        pr_err("\t%d: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u %s\n",
                cpu, ticks_value, ticks_title,
                atomic_read(&rdtp->dynticks) & 0xfff,
                rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting,
@@ -1925,7 +1950,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
 /* Terminate the stall-info list. */
 static void print_cpu_stall_info_end(void)
 {
-        printk(KERN_ERR "\t");
+        pr_err("\t");
 }
 
 /* Zero ->ticks_this_gp for all flavors of RCU. */
@@ -1948,17 +1973,17 @@ static void increment_cpu_stall_ticks(void)
 
 static void print_cpu_stall_info_begin(void)
 {
-        printk(KERN_CONT " {");
+        pr_cont(" {");
 }
 
 static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
 {
-        printk(KERN_CONT " %d", cpu);
+        pr_cont(" %d", cpu);
 }
 
 static void print_cpu_stall_info_end(void)
 {
-        printk(KERN_CONT "} ");
+        pr_cont("} ");
 }
 
 static void zero_cpu_stall_ticks(struct rcu_data *rdp)