[PATCH] Deprecate synchronize_kernel, GPL replacement (9b06e818) · Commits · 戴 / test

include/linux/rcupdate.h

+20 −3

Original line number	Diff line number	Diff line
		@@ -157,9 +157,9 @@ static inline int rcu_pending(int cpu)
		/**
		* rcu_read_lock - mark the beginning of an RCU read-side critical section.
		*
		* When synchronize_kernel() is invoked on one CPU while other CPUs
		* When synchronize_rcu() is invoked on one CPU while other CPUs
		* are within RCU read-side critical sections, then the
		* synchronize_kernel() is guaranteed to block until after all the other
		* synchronize_rcu() is guaranteed to block until after all the other
		* CPUs exit their critical sections. Similarly, if call_rcu() is invoked
		* on one CPU while other CPUs are within RCU read-side critical
		* sections, invocation of the corresponding RCU callback is deferred
		@@ -256,6 +256,21 @@ static inline int rcu_pending(int cpu)
		(p) = (v); \
		})

		/**
		* synchronize_sched - block until all CPUs have exited any non-preemptive
		* kernel code sequences.
		*
		* This means that all preempt_disable code sequences, including NMI and
		* hardware-interrupt handlers, in progress on entry will have completed
		* before this primitive returns. However, this does not guarantee that
		* softirq handlers will have completed, since in some kernels
		*
		* This primitive provides the guarantees made by the (deprecated)
		* synchronize_kernel() API. In contrast, synchronize_rcu() only
		* guarantees that rcu_read_lock() sections will have completed.
		*/
		#define synchronize_sched() synchronize_rcu()

		extern void rcu_init(void);
		extern void rcu_check_callbacks(int cpu, int user);
		extern void rcu_restart_cpu(int cpu);
		@@ -265,7 +280,9 @@ extern void FASTCALL(call_rcu(struct rcu_head *head,
		void (func)(struct rcu_head head)));
		extern void FASTCALL(call_rcu_bh(struct rcu_head *head,
		void (func)(struct rcu_head head)));
		extern void synchronize_kernel(void);
		extern __deprecated_for_modules void synchronize_kernel(void);
		extern void synchronize_rcu(void);
		void synchronize_idle(void);

		#endif /* __KERNEL__ */
		#endif /* __LINUX_RCUPDATE_H */

kernel/rcupdate.c

+14 −2

Original line number	Diff line number	Diff line
		@@ -444,15 +444,18 @@ static void wakeme_after_rcu(struct rcu_head *head)
		}

		/**
		* synchronize_kernel - wait until a grace period has elapsed.
		* synchronize_rcu - wait until a grace period has elapsed.
		*
		* Control will return to the caller some time after a full grace
		* period has elapsed, in other words after all currently executing RCU
		* read-side critical sections have completed. RCU read-side critical
		* sections are delimited by rcu_read_lock() and rcu_read_unlock(),
		* and may be nested.
		*
		* If your read-side code is not protected by rcu_read_lock(), do -not-
		* use synchronize_rcu().
		*/
		void synchronize_kernel(void)
		void synchronize_rcu(void)
		{
		struct rcu_synchronize rcu;

		@@ -464,7 +467,16 @@ void synchronize_kernel(void)
		wait_for_completion(&rcu.completion);
		}

		/*
		* Deprecated, use synchronize_rcu() or synchronize_sched() instead.
		*/
		void synchronize_kernel(void)
		{
		synchronize_rcu();
		}

		module_param(maxbatch, int, 0);
		EXPORT_SYMBOL(call_rcu); /* WARNING: GPL-only in April 2006. */
		EXPORT_SYMBOL(call_rcu_bh); /* WARNING: GPL-only in April 2006. */
		EXPORT_SYMBOL_GPL(synchronize_rcu);
		EXPORT_SYMBOL(synchronize_kernel); /* WARNING: GPL-only in April 2006. */

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