rcu_sync: Cleanup the CONFIG_PROVE_RCU checks (4bace734) · Commits · 戴 / test

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:

Oleg Nesterov <oleg@redhat.com> Signed-off-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:

Josh Triplett <josh@joshtriplett.org>

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

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