From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Fri, 20 Mar 2015 15:31:01 +0000 (-0700)
Subject: Merge branches 'doc.2015.02.26a', 'earlycb.2015.03.03a', 'fixes.2015.03.03a', 'gpexp... 
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=42528795ac1c8d7ba021797ec004904168956d64;p=linux-beck.git

Merge branches 'doc.2015.02.26a', 'earlycb.2015.03.03a', 'fixes.2015.03.03a', 'gpexp.2015.02.26a', 'hotplug.2015.03.20a', 'sysidle.2015.02.26b' and 'tiny.2015.02.26a' into HEAD

doc.2015.02.26a:  Documentation changes
earlycb.2015.03.03a:  Permit early-boot RCU callbacks
fixes.2015.03.03a:  Miscellaneous fixes
gpexp.2015.02.26a:  In-kernel expediting of normal grace periods
hotplug.2015.03.20a:  CPU hotplug fixes
sysidle.2015.02.26b:  NO_HZ_FULL_SYSIDLE fixes
tiny.2015.02.26a:  TINY_RCU fixes
---

42528795ac1c8d7ba021797ec004904168956d64
diff --cc kernel/rcu/tree.c
index 48d640ca1a05,c8e6569c5fbd,23194a77a768,4325fbe79d84,8fcc64ed858c,a6972c20eaa5,48d640ca1a05..233165da782f
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@@@@@@@ -101,11 -103,10 -101,11 -101,11 -101,10 -101,11 -101,11 +103,9 @@@@@@@@ struct rcu_state sname##_state = { 
       	.orphan_nxttail = &sname##_state.orphan_nxtlist, \
       	.orphan_donetail = &sname##_state.orphan_donelist, \
       	.barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
---- --	.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
       	.name = RCU_STATE_NAME(sname), \
       	.abbr = sabbr, \
- -----}; \
- -----DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, sname##_data)
+ +++++}
       
       RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
       RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
@@@@@@@@ -3734,30 -3757,30 -3734,26 -3735,30 -3900,30 -3734,30 -3734,30 +3924,26 @@@@@@@@ void rcu_scheduler_starting(void
        * Compute the per-level fanout, either using the exact fanout specified
        * or balancing the tree, depending on CONFIG_RCU_FANOUT_EXACT.
        */
-- ----#ifdef CONFIG_RCU_FANOUT_EXACT
-- - --static void __init rcu_init_levelspread(struct rcu_state *rsp)
-- - --{
-- - --	int i;
-- - --
-- - --	rsp->levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
-- - --	for (i = rcu_num_lvls - 2; i >= 0; i--)
-- - --		rsp->levelspread[i] = CONFIG_RCU_FANOUT;
-- - --}
-- - --#else /* #ifdef CONFIG_RCU_FANOUT_EXACT */
       static void __init rcu_init_levelspread(struct rcu_state *rsp)
       {
-- - --	int ccur;
-- - --	int cprv;
       	int i;
       
    -  	rsp->levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
    -  	for (i = rcu_num_lvls - 2; i >= 0; i--)
    -  		rsp->levelspread[i] = CONFIG_RCU_FANOUT;
    -  }
    -  #else /* #ifdef CONFIG_RCU_FANOUT_EXACT */
    -  static void __init rcu_init_levelspread(struct rcu_state *rsp)
    -  {
    -  	int ccur;
    -  	int cprv;
    -  	int i;
    -  
-- ----	cprv = nr_cpu_ids;
-- ----	for (i = rcu_num_lvls - 1; i >= 0; i--) {
-- ----		ccur = rsp->levelcnt[i];
-- ----		rsp->levelspread[i] = (cprv + ccur - 1) / ccur;
-- ----		cprv = ccur;
++ ++++	if (IS_ENABLED(CONFIG_RCU_FANOUT_EXACT)) {
++ ++++		rsp->levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
++ ++++		for (i = rcu_num_lvls - 2; i >= 0; i--)
++ ++++			rsp->levelspread[i] = CONFIG_RCU_FANOUT;
++ ++++	} else {
++ ++++		int ccur;
++ ++++		int cprv;
++ ++++
++ ++++		cprv = nr_cpu_ids;
++ ++++		for (i = rcu_num_lvls - 1; i >= 0; i--) {
++ ++++			ccur = rsp->levelcnt[i];
++ ++++			rsp->levelspread[i] = (cprv + ccur - 1) / ccur;
++ ++++			cprv = ccur;
++ ++++		}
       	}
       }
-- ----#endif /* #else #ifdef CONFIG_RCU_FANOUT_EXACT */
       
       /*
        * Helper function for rcu_init() that initializes one rcu_state structure.
diff --cc kernel/rcu/tree_plugin.h
index 0a571e9a0f1d,afddd5641bea,c9225350d3ed,63726b734d34,d45e961515c1,b46c92824db1,0a571e9a0f1d..8c0ec0f5a027
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@@@@@@@ -757,19 -757,19 -758,19 -757,19 -759,16 -757,19 -757,19 +760,16 @@@@@@@@ void synchronize_rcu_expedited(void
       	/* force all RCU readers onto ->blkd_tasks lists. */
       	synchronize_sched_expedited();
       
---- --	/* Initialize ->expmask for all non-leaf rcu_node structures. */
---- --	rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) {
---- --		raw_spin_lock_irqsave(&rnp->lock, flags);
---- --		smp_mb__after_unlock_lock();
---- --		rnp->expmask = rnp->qsmaskinit;
---- --		raw_spin_unlock_irqrestore(&rnp->lock, flags);
---- --	}
---- --
---- --	/* Snapshot current state of ->blkd_tasks lists. */
++++ ++	/*
++++ ++	 * Snapshot current state of ->blkd_tasks lists into ->expmask.
++++ ++	 * Phase 1 sets bits and phase 2 permits rcu_read_unlock_special()
++++ ++	 * to start clearing them.  Doing this in one phase leads to
++++ ++	 * strange races between setting and clearing bits, so just say "no"!
++++ ++	 */
++ + ++	rcu_for_each_leaf_node(rsp, rnp)
  -    		sync_rcu_preempt_exp_init(rsp, rnp);
  -    	if (NUM_RCU_NODES > 1)
  -    		sync_rcu_preempt_exp_init(rsp, rcu_get_root(rsp));
++++ ++		sync_rcu_preempt_exp_init1(rsp, rnp);
  +    	rcu_for_each_leaf_node(rsp, rnp)
-- - --		sync_rcu_preempt_exp_init(rsp, rnp);
-- - --	if (NUM_RCU_NODES > 1)
-- - --		sync_rcu_preempt_exp_init(rsp, rcu_get_root(rsp));
++++ ++		sync_rcu_preempt_exp_init2(rsp, rnp);
       
       	put_online_cpus();