Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm

[linux-flexiantxendom0-3.2.10.git] / kernel / rcutiny.c

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index e5bd949..37a5444 100644 (file)
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -53,7 +53,7 @@ static void __call_rcu(struct rcu_head *head,
 
 #include "rcutiny_plugin.h"
 
-static long long rcu_dynticks_nesting = DYNTICK_TASK_NESTING;
+static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
 
 /* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
 static void rcu_idle_enter_common(long long oldval)
@@ -88,10 +88,16 @@ void rcu_idle_enter(void)
 
        local_irq_save(flags);
        oldval = rcu_dynticks_nesting;
-       rcu_dynticks_nesting = 0;
+       WARN_ON_ONCE((rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK) == 0);
+       if ((rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK) ==
+           DYNTICK_TASK_NEST_VALUE)
+               rcu_dynticks_nesting = 0;
+       else
+               rcu_dynticks_nesting  -= DYNTICK_TASK_NEST_VALUE;
        rcu_idle_enter_common(oldval);
        local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_enter);
 
 /*
  * Exit an interrupt handler towards idle.
@@ -140,11 +146,15 @@ void rcu_idle_exit(void)
 
        local_irq_save(flags);
        oldval = rcu_dynticks_nesting;
-       WARN_ON_ONCE(oldval != 0);
-       rcu_dynticks_nesting = DYNTICK_TASK_NESTING;
+       WARN_ON_ONCE(rcu_dynticks_nesting < 0);
+       if (rcu_dynticks_nesting & DYNTICK_TASK_NEST_MASK)
+               rcu_dynticks_nesting += DYNTICK_TASK_NEST_VALUE;
+       else
+               rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
        rcu_idle_exit_common(oldval);
        local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_exit);
 
 /*
  * Enter an interrupt handler, moving away from idle.
@@ -258,14 +268,18 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 
        /* If no RCU callbacks ready to invoke, just return. */
        if (&rcp->rcucblist == rcp->donetail) {
-               RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, -1));
-               RCU_TRACE(trace_rcu_batch_end(rcp->name, 0));
+               RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, 0, -1));
+               RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
+                                             ACCESS_ONCE(rcp->rcucblist),
+                                             need_resched(),
+                                             is_idle_task(current),
+                                             rcu_is_callbacks_kthread()));
                return;
        }
 
        /* Move the ready-to-invoke callbacks to a local list. */
        local_irq_save(flags);
-       RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, -1));
+       RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1));
        list = rcp->rcucblist;
        rcp->rcucblist = *rcp->donetail;
        *rcp->donetail = NULL;
@@ -288,7 +302,9 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
                RCU_TRACE(cb_count++);
        }
        RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count));
-       RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count));
+       RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count, 0, need_resched(),
+                                     is_idle_task(current),
+                                     rcu_is_callbacks_kthread()));
 }
 
 static void rcu_process_callbacks(struct softirq_action *unused)
@@ -313,6 +329,10 @@ static void rcu_process_callbacks(struct softirq_action *unused)
  */
 void synchronize_sched(void)
 {
+       rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) &&
+                          !lock_is_held(&rcu_lock_map) &&
+                          !lock_is_held(&rcu_sched_lock_map),
+                          "Illegal synchronize_sched() in RCU read-side critical section");
        cond_resched();
 }
 EXPORT_SYMBOL_GPL(synchronize_sched);