RCU: Don't try and predeclare inline funcs as it upsets some versions of gcc (5b1d07ed) · Commits · 戴 / test

Don't try and predeclare inline funcs like this: static inline void wait_migrated_callbacks(void) ... static void _rcu_barrier(enum rcu_barrier type) { ... wait_migrated_callbacks(); } ... static inline void wait_migrated_callbacks(void) { wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count)); } as it upsets some versions of gcc under some circumstances: kernel/rcupdate.c: In function `_rcu_barrier': kernel/rcupdate.c:125: sorry, unimplemented: inlining failed in call to 'wait_migrated_callbacks': function body not available kernel/rcupdate.c:152: sorry, unimplemented: called from here This can be dealt with by simply putting the static variables (rcu_migrate_*) at the top, and moving the implementation of the function up so that it replaces its forward declaration. Signed-off-by:

David Howells <dhowells@redhat.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/rcupdate.c

+8 −10

Original line number	Diff line number	Diff line
		@@ -58,6 +58,10 @@ static DEFINE_MUTEX(rcu_barrier_mutex);
		static struct completion rcu_barrier_completion;
		int rcu_scheduler_active __read_mostly;

		static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
		static struct rcu_head rcu_migrate_head[3];
		static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);

		/*
		* Awaken the corresponding synchronize_rcu() instance now that a
		* grace period has elapsed.
		@@ -122,7 +126,10 @@ static void rcu_barrier_func(void *type)
		}
		}

		static inline void wait_migrated_callbacks(void);
		static inline void wait_migrated_callbacks(void)
		{
		wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
		}

		/*
		* Orchestrate the specified type of RCU barrier, waiting for all
		@@ -179,21 +186,12 @@ void rcu_barrier_sched(void)
		}
		EXPORT_SYMBOL_GPL(rcu_barrier_sched);

		static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
		static struct rcu_head rcu_migrate_head[3];
		static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);

		static void rcu_migrate_callback(struct rcu_head *notused)
		{
		if (atomic_dec_and_test(&rcu_migrate_type_count))
		wake_up(&rcu_migrate_wq);
		}

		static inline void wait_migrated_callbacks(void)
		{
		wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
		}

		static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
		unsigned long action, void *hcpu)
		{

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