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

Pull RCU changes from Ingo Molnar:
 "The main RCU changes in this cycle were:

   - RCU torture-test changes.

   - variable-name renaming cleanup.

   - update RCU documentation.

   - miscellaneous fixes.

   - patch to suppress RCU stall warnings while sysrq requests are being
     processed"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
  rcu: Provide API to suppress stall warnings while sysrc runs
  rcu: Variable name changed in tree_plugin.h and used in tree.c
  torture: Remove unused definition
  torture: Remove __init from torture_init_begin/end
  torture: Check for multiple concurrent torture tests
  locktorture: Remove reference to nonexistent Kconfig parameter
  rcutorture: Run rcu_torture_writer at normal priority
  rcutorture: Note diffs from git commits
  rcutorture: Add missing destroy_timer_on_stack()
  rcutorture: Explicitly test synchronous grace-period primitives
  rcutorture:  Add tests for get_state_synchronize_rcu()
  rcutorture: Test RCU-sched primitives in TREE_PREEMPT_RCU kernels
  torture: Use elapsed time to detect hangs
  rcutorture: Check for rcu_torture_fqs creation errors
  torture: Better summary diagnostics for build failures
  torture: Notice if an all-zero cpumask is passed inside a critical section
  rcutorture: Make rcu_torture_reader() use cond_resched()
  sched,rcu: Make cond_resched() report RCU quiescent states
  percpu: Fix raw_cpu_inc_return()
  rcutorture: Export RCU grace-period kthread wait state to rcutorture
  ...

1 files changed, 7 insertions, 4 deletions

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 75dc3c39a02a..bf2c1e669691 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -252,7 +252,6 @@ struct rcu_data {
         bool            passed_quiesce; /* User-mode/idle loop etc. */
         bool            qs_pending;     /* Core waits for quiesc state. */
         bool            beenonline;     /* CPU online at least once. */
-        bool            preemptible;    /* Preemptible RCU? */
         struct rcu_node *mynode;        /* This CPU's leaf of hierarchy */
         unsigned long grpmask;          /* Mask to apply to leaf qsmask. */
 #ifdef CONFIG_RCU_CPU_STALL_INFO
@@ -406,7 +405,8 @@ struct rcu_state {
         unsigned long completed;                /* # of last completed gp. */
         struct task_struct *gp_kthread;         /* Task for grace periods. */
         wait_queue_head_t gp_wq;                /* Where GP task waits. */
-        int gp_flags;                           /* Commands for GP task. */
+        short gp_flags;                         /* Commands for GP task. */
+        short gp_state;                         /* GP kthread sleep state. */
 
         /* End of fields guarded by root rcu_node's lock. */
 
@@ -462,13 +462,17 @@ struct rcu_state {
         const char *name;                       /* Name of structure. */
         char abbr;                              /* Abbreviated name. */
         struct list_head flavors;               /* List of RCU flavors. */
-        struct irq_work wakeup_work;            /* Postponed wakeups */
 };
 
 /* Values for rcu_state structure's gp_flags field. */
 #define RCU_GP_FLAG_INIT 0x1    /* Need grace-period initialization. */
 #define RCU_GP_FLAG_FQS  0x2    /* Need grace-period quiescent-state forcing. */
 
+/* Values for rcu_state structure's gp_flags field. */
+#define RCU_GP_WAIT_INIT 0      /* Initial state. */
+#define RCU_GP_WAIT_GPS  1      /* Wait for grace-period start. */
+#define RCU_GP_WAIT_FQS  2      /* Wait for force-quiescent-state time. */
+
 extern struct list_head rcu_struct_flavors;
 
 /* Sequence through rcu_state structures for each RCU flavor. */
@@ -547,7 +551,6 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu);
 static void print_cpu_stall_info_end(void);
 static void zero_cpu_stall_ticks(struct rcu_data *rdp);
 static void increment_cpu_stall_ticks(void);
-static int rcu_nocb_needs_gp(struct rcu_state *rsp);
 static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq);
 static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp);
 static void rcu_init_one_nocb(struct rcu_node *rnp);