Merge branch 'poll' into staging/for_v3.4

* poll: (5970 commits)
  poll: add poll_requested_events() and poll_does_not_wait() functions
  crc32: select an algorithm via Kconfig
  crc32: add self-test code for crc32c
  crypto: crc32c should use library implementation
  crc32: bolt on crc32c
  crc32: add note about this patchset to crc32.c
  crc32: optimize loop counter for x86
  crc32: add slice-by-8 algorithm to existing code
  crc32: make CRC_*_BITS definition correspond to actual bit counts
  crc32: fix mixing of endian-specific types
  crc32: miscellaneous cleanups
  crc32: simplify unit test code
  crc32: move long comment about crc32 fundamentals to Documentation/
  crc32: remove two instances of trailing whitespaces
  checkpatch: check for quoted strings broken across lines
  checkpatch: whitespace - add/remove blank lines
  checkpatch: warn on use of yield()
  checkpatch: add --strict tests for braces, comments and casts
  checkpatch: add [] to type extensions
  checkpatch: high precedence operators do not require additional parentheses in #defines
  ...

1 files changed, 20 insertions, 6 deletions

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index 977296dca0a4..37a5444204d2 100644
--- 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.
@@ -258,7 +268,7 @@ 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_start(rcp->name, 0, 0, -1));
 		RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
 					      ACCESS_ONCE(rcp->rcucblist),
 					      need_resched(),
@@ -269,7 +279,7 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 
 	/* 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;
@@ -319,6 +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);