From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Tue, 15 May 2018 17:33:05 +0000 (-0700)
Subject: Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' and 'tortur... 
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=22df7316ac71dc1ac57415349938737d2a229c59;p=linux.git

Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' and 'torture.2018.05.15a' into HEAD

exp.2018.05.15a: Parallelize expedited grace-period initialization.
fixes.2018.05.15a: Miscellaneous fixes.
lock.2018.05.15a: Decrease lock contention on root rcu_node structure,
	which is a step towards merging RCU flavors.
torture.2018.05.15a: Torture-test updates.
---

22df7316ac71dc1ac57415349938737d2a229c59
diff --cc kernel/rcu/tree.h
index 98d33902b65c9,0b3a90ebe225e,9f97fd7f648c7,f491ab4f2e8ec..78e051dffc5bf
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@@@@ -165,10 -157,8 -156,24 -157,8 +164,26 @@@@@ struct rcu_node 
    	spinlock_t exp_lock ____cacheline_internodealigned_in_smp;
    	unsigned long exp_seq_rq;
    	wait_queue_head_t exp_wq[4];
 +++	struct rcu_exp_work rew;
 +++	bool exp_need_flush;	/* Need to flush workitem? */
    } ____cacheline_internodealigned_in_smp;
    
++ +/* Accessors for ->need_future_gp[] array. */
++ +#define need_future_gp_mask() \
++ +	(ARRAY_SIZE(((struct rcu_node *)NULL)->need_future_gp) - 1)
++ +#define need_future_gp_element(rnp, c) \
++ +	((rnp)->need_future_gp[(c) & need_future_gp_mask()])
++ +#define need_any_future_gp(rnp)						\
++ +({									\
++ +	int __i;							\
++ +	bool __nonzero = false;						\
++ +									\
++ +	for (__i = 0; __i < ARRAY_SIZE((rnp)->need_future_gp); __i++)	\
++ +		__nonzero = __nonzero ||				\
++ +			    READ_ONCE((rnp)->need_future_gp[__i]);	\
++ +	__nonzero;							\
++ +})
++ +
    /*
     * Bitmasks in an rcu_node cover the interval [grplo, grphi] of CPU IDs, and
     * are indexed relative to this interval rather than the global CPU ID space.