Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU changes from Ingo Molnar:

 0. 'idle RCU':

     Adds RCU APIs that allow non-idle tasks to enter RCU idle mode and
     provides x86 code to make use of them, allowing RCU to treat
     user-mode execution as an extended quiescent state when the new
     RCU_USER_QS kernel configuration parameter is specified.  (Work is
     in progress to port this to a few other architectures, but is not
     part of this series.)

 1.  A fix for a latent bug that has been in RCU ever since the addition
     of CPU stall warnings.  This bug results in false-positive stall
     warnings, but thus far only on embedded systems with severely
     cut-down userspace configurations.

 2.  Further reductions in latency spikes for huge systems, along with
     additional boot-time adaptation to the actual hardware.

     This is a large change, as it moves RCU grace-period initialization
     and cleanup, along with quiescent-state forcing, from softirq to a
     kthread.  However, it appears to be in quite good shape (famous
     last words).

 3.  Updates to documentation and rcutorture, the latter category
     including keeping statistics on CPU-hotplug latencies and fixing
     some initialization-time races.

 4.  CPU-hotplug fixes and improvements.

 5.  Idle-loop fixes that were omitted on an earlier submission.

 6.  Miscellaneous fixes and improvements

In certain RCU configurations new kernel threads will show up (rcu_bh,
rcu_sched), showing RCU processing overhead.

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (90 commits)
  rcu: Apply micro-optimization and int/bool fixes to RCU's idle handling
  rcu: Userspace RCU extended QS selftest
  x86: Exit RCU extended QS on notify resume
  x86: Use the new schedule_user API on userspace preemption
  rcu: Exit RCU extended QS on user preemption
  rcu: Exit RCU extended QS on kernel preemption after irq/exception
  x86: Exception hooks for userspace RCU extended QS
  x86: Unspaghettize do_general_protection()
  x86: Syscall hooks for userspace RCU extended QS
  rcu: Switch task's syscall hooks on context switch
  rcu: Ignore userspace extended quiescent state by default
  rcu: Allow rcu_user_enter()/exit() to nest
  rcu: Settle config for userspace extended quiescent state
  rcu: Make RCU_FAST_NO_HZ handle adaptive ticks
  rcu: New rcu_user_enter_after_irq() and rcu_user_exit_after_irq() APIs
  rcu: New rcu_user_enter() and rcu_user_exit() APIs
  ia64: Add missing RCU idle APIs on idle loop
  xtensa: Add missing RCU idle APIs on idle loop
  score: Add missing RCU idle APIs on idle loop
  parisc: Add missing RCU idle APIs on idle loop
  ...

1 files changed, 9 insertions, 13 deletions

diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index abffb486e94e..693513bc50e6 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -51,8 +51,8 @@ static int show_rcubarrier(struct seq_file *m, void *unused)
 	struct rcu_state *rsp;
 
 	for_each_rcu_flavor(rsp)
-		seq_printf(m, "%s: %c bcc: %d nbd: %lu\n",
-			   rsp->name, rsp->rcu_barrier_in_progress ? 'B' : '.',
+		seq_printf(m, "%s: bcc: %d nbd: %lu\n",
+			   rsp->name,
 			   atomic_read(&rsp->barrier_cpu_count),
 			   rsp->n_barrier_done);
 	return 0;
@@ -86,12 +86,11 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
 {
 	if (!rdp->beenonline)
 		return;
-	seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pgp=%lu qp=%d",
+	seq_printf(m, "%3d%cc=%lu g=%lu pq=%d qp=%d",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
 		   rdp->completed, rdp->gpnum,
-		   rdp->passed_quiesce, rdp->passed_quiesce_gpnum,
-		   rdp->qs_pending);
+		   rdp->passed_quiesce, rdp->qs_pending);
 	seq_printf(m, " dt=%d/%llx/%d df=%lu",
 		   atomic_read(&rdp->dynticks->dynticks),
 		   rdp->dynticks->dynticks_nesting,
@@ -108,11 +107,10 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
 			rdp->nxttail[RCU_WAIT_TAIL]],
 		   ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
 #ifdef CONFIG_RCU_BOOST
-	seq_printf(m, " kt=%d/%c/%d ktl=%x",
+	seq_printf(m, " kt=%d/%c ktl=%x",
 		   per_cpu(rcu_cpu_has_work, rdp->cpu),
 		   convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
 					  rdp->cpu)),
-		   per_cpu(rcu_cpu_kthread_cpu, rdp->cpu),
 		   per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
 #endif /* #ifdef CONFIG_RCU_BOOST */
 	seq_printf(m, " b=%ld", rdp->blimit);
@@ -150,12 +148,11 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
 {
 	if (!rdp->beenonline)
 		return;
-	seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
+	seq_printf(m, "%d,%s,%lu,%lu,%d,%d",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
 		   rdp->completed, rdp->gpnum,
-		   rdp->passed_quiesce, rdp->passed_quiesce_gpnum,
-		   rdp->qs_pending);
+		   rdp->passed_quiesce, rdp->qs_pending);
 	seq_printf(m, ",%d,%llx,%d,%lu",
 		   atomic_read(&rdp->dynticks->dynticks),
 		   rdp->dynticks->dynticks_nesting,
@@ -186,7 +183,7 @@ static int show_rcudata_csv(struct seq_file *m, void *unused)
 	int cpu;
 	struct rcu_state *rsp;
 
-	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pgp\",\"pq\",");
+	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pq\",");
 	seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
 	seq_puts(m, "\"of\",\"qll\",\"ql\",\"qs\"");
 #ifdef CONFIG_RCU_BOOST
@@ -386,10 +383,9 @@ static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
 		   rdp->n_rp_report_qs,
 		   rdp->n_rp_cb_ready,
 		   rdp->n_rp_cpu_needs_gp);
-	seq_printf(m, "gpc=%ld gps=%ld nf=%ld nn=%ld\n",
+	seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n",
 		   rdp->n_rp_gp_completed,
 		   rdp->n_rp_gp_started,
-		   rdp->n_rp_need_fqs,
 		   rdp->n_rp_need_nothing);
 }