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Commit 4bace734 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Paul E. McKenney
Browse files

rcu_sync: Cleanup the CONFIG_PROVE_RCU checks 



1. Rename __rcu_sync_is_idle() to rcu_sync_lockdep_assert() and
   change it to use rcu_lockdep_assert().

2. Change rcu_sync_is_idle() to return rsp->gp_state == GP_IDLE
   unconditonally, this way we can remove the same check from
   rcu_sync_lockdep_assert() and clearly isolate the debugging
   code.

Note: rcu_sync_enter()->wait_event(gp_state == GP_PASSED) needs
another CONFIG_PROVE_RCU check, the same as is done in ->sync(); but
this needs some simple preparations in the core RCU code to avoid the
code duplication.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent cc5f730b

include/linux/rcu_sync.h

+3 −4
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct rcu_sync { 
	enum rcu_sync_type	gp_type;

};



extern bool __rcu_sync_is_idle(struct rcu_sync *);

extern void rcu_sync_lockdep_assert(struct rcu_sync *);



/**

 * rcu_sync_is_idle() - Are readers permitted to use their fastpaths?
@@ -53,10 +53,9 @@ extern bool __rcu_sync_is_idle(struct rcu_sync *); 
static inline bool rcu_sync_is_idle(struct rcu_sync *rsp)

{

#ifdef CONFIG_PROVE_RCU

	return __rcu_sync_is_idle(rsp);

#else

	return !rsp->gp_state; /* GP_IDLE */

	rcu_sync_lockdep_assert(rsp);

#endif

	return !rsp->gp_state; /* GP_IDLE */

}



extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type);

kernel/rcu/sync.c

+3 −3
Original line number Diff line number Diff line
@@ -63,10 +63,10 @@ enum { CB_IDLE = 0, CB_PENDING, CB_REPLAY }; 
#define	rss_lock	gp_wait.lock



#ifdef CONFIG_PROVE_RCU

bool __rcu_sync_is_idle(struct rcu_sync *rsp)

void rcu_sync_lockdep_assert(struct rcu_sync *rsp)

{

	WARN_ON(!gp_ops[rsp->gp_type].held());

	return rsp->gp_state == GP_IDLE;

	RCU_LOCKDEP_WARN(!gp_ops[rsp->gp_type].held(),

			 "suspicious rcu_sync_is_idle() usage");

}

#endif