Merge branch 'core-fixes-for-linus' of... (b8c7f1dc) · Commits · 戴 / test

include/linux/rcupdate.h

+8 −21

Original line number	Diff line number	Diff line
		@@ -52,8 +52,13 @@ struct rcu_head {
		};

		/* Exported common interfaces */
		#ifdef CONFIG_TREE_PREEMPT_RCU
		extern void synchronize_rcu(void);
		#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
		#define synchronize_rcu synchronize_sched
		#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
		extern void synchronize_rcu_bh(void);
		extern void synchronize_sched(void);
		extern void rcu_barrier(void);
		extern void rcu_barrier_bh(void);
		extern void rcu_barrier_sched(void);
		@@ -261,24 +266,6 @@ struct rcu_synchronize {

		extern void wakeme_after_rcu(struct rcu_head *head);

		/**
		* 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, these
		* handlers can run in process context, and can block.
		*
		* This primitive provides the guarantees made by the (now removed)
		* synchronize_kernel() API. In contrast, synchronize_rcu() only
		* guarantees that rcu_read_lock() sections will have completed.
		* In "classic RCU", these two guarantees happen to be one and
		* the same, but can differ in realtime RCU implementations.
		*/
		#define synchronize_sched() __synchronize_sched()

		/**
		* call_rcu - Queue an RCU callback for invocation after a grace period.
		* @head: structure to be used for queueing the RCU updates.

include/linux/rcutree.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -53,6 +53,8 @@ static inline void __rcu_read_unlock(void)
		preempt_enable();
		}

		#define __synchronize_sched() synchronize_rcu()

		static inline void exit_rcu(void)
		{
		}
		@@ -68,8 +70,6 @@ static inline void __rcu_read_unlock_bh(void)
		local_bh_enable();
		}

		#define __synchronize_sched() synchronize_rcu()

		extern void call_rcu_sched(struct rcu_head *head,
		void (func)(struct rcu_head rcu));

include/linux/sched.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -1755,7 +1755,6 @@ extern cputime_t task_gtime(struct task_struct *p);

		#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
		#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
		#define RCU_READ_UNLOCK_GOT_QS (1 << 2) /* CPU has responded to RCU core. */

		static inline void rcu_copy_process(struct task_struct *p)
		{

init/Kconfig

+2 −1

Original line number	Diff line number	Diff line
		@@ -331,7 +331,8 @@ config TREE_PREEMPT_RCU
		This option selects the RCU implementation that is
		designed for very large SMP systems with hundreds or
		thousands of CPUs, but for which real-time response
		is also required.
		is also required. It also scales down nicely to
		smaller systems.

		endchoice

kernel/rcupdate.c

+45 −3

Original line number	Diff line number	Diff line
		@@ -74,6 +74,8 @@ void wakeme_after_rcu(struct rcu_head *head)
		complete(&rcu->completion);
		}

		#ifdef CONFIG_TREE_PREEMPT_RCU

		/**
		* synchronize_rcu - wait until a grace period has elapsed.
		*
		@@ -87,7 +89,7 @@ void synchronize_rcu(void)
		{
		struct rcu_synchronize rcu;

		if (rcu_blocking_is_gp())
		if (!rcu_scheduler_active)
		return;

		init_completion(&rcu.completion);
		@@ -98,6 +100,46 @@ void synchronize_rcu(void)
		}
		EXPORT_SYMBOL_GPL(synchronize_rcu);

		#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */

		/**
		* synchronize_sched - wait until an rcu-sched grace period has elapsed.
		*
		* Control will return to the caller some time after a full rcu-sched
		* grace period has elapsed, in other words after all currently executing
		* rcu-sched read-side critical sections have completed. These read-side
		* critical sections are delimited by rcu_read_lock_sched() and
		* rcu_read_unlock_sched(), and may be nested. Note that preempt_disable(),
		* local_irq_disable(), and so on may be used in place of
		* rcu_read_lock_sched().
		*
		* 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, these
		* handlers can run in process context, and can block.
		*
		* This primitive provides the guarantees made by the (now removed)
		* synchronize_kernel() API. In contrast, synchronize_rcu() only
		* guarantees that rcu_read_lock() sections will have completed.
		* In "classic RCU", these two guarantees happen to be one and
		* the same, but can differ in realtime RCU implementations.
		*/
		void synchronize_sched(void)
		{
		struct rcu_synchronize rcu;

		if (rcu_blocking_is_gp())
		return;

		init_completion(&rcu.completion);
		/* Will wake me after RCU finished. */
		call_rcu_sched(&rcu.head, wakeme_after_rcu);
		/* Wait for it. */
		wait_for_completion(&rcu.completion);
		}
		EXPORT_SYMBOL_GPL(synchronize_sched);

		/**
		* synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
		*

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