Merge branches 'rcu/fixes', 'rcu/nocb', 'rcu/torture', 'rcu/stall' and 'rcu/srcu' into rcu/dev (d8dfba2c) · Commits · git / linux-net

Documentation/admin-guide/kernel-parameters.txt

+8 −0

Original line number	Diff line number	Diff line
		@@ -5421,6 +5421,14 @@
		The delay, in seconds, between successive
		read-then-exit testing episodes.

		rcutorture.reader_flavor= [KNL]
		A bit mask indicating which readers to use.
		If there is more than one bit set, the readers
		are entered from low-order bit up, and are
		exited in the opposite order. For SRCU, the
		0x1 bit is normal readers, 0x2 NMI-safe readers,
		and 0x4 light-weight readers.

		rcutorture.shuffle_interval= [KNL]
		Set task-shuffle interval (s). Shuffling tasks
		allows some CPUs to go into dyntick-idle mode

include/linux/rcutiny.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -165,7 +165,6 @@ static inline bool rcu_inkernel_boot_has_ended(void) { return true; }
		static inline bool rcu_is_watching(void) { return true; }
		static inline void rcu_momentary_eqs(void) { }
		static inline void kfree_rcu_scheduler_running(void) { }
		static inline bool rcu_gp_might_be_stalled(void) { return false; }

		/* Avoid RCU read-side critical sections leaking across. */
		static inline void rcu_all_qs(void) { barrier(); }

include/linux/rcutree.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -40,7 +40,6 @@ void kvfree_rcu_barrier(void);
		void rcu_barrier(void);
		void rcu_momentary_eqs(void);
		void kfree_rcu_scheduler_running(void);
		bool rcu_gp_might_be_stalled(void);

		struct rcu_gp_oldstate {
		unsigned long rgos_norm;

include/linux/srcu.h

+69 −23

Original line number	Diff line number	Diff line
		@@ -56,6 +56,13 @@ void call_srcu(struct srcu_struct ssp, struct rcu_head head,
		void cleanup_srcu_struct(struct srcu_struct *ssp);
		int __srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp);
		void __srcu_read_unlock(struct srcu_struct *ssp, int idx) __releases(ssp);
		#ifdef CONFIG_TINY_SRCU
		#define __srcu_read_lock_lite __srcu_read_lock
		#define __srcu_read_unlock_lite __srcu_read_unlock
		#else // #ifdef CONFIG_TINY_SRCU
		int __srcu_read_lock_lite(struct srcu_struct *ssp) __acquires(ssp);
		void __srcu_read_unlock_lite(struct srcu_struct *ssp, int idx) __releases(ssp);
		#endif // #else // #ifdef CONFIG_TINY_SRCU
		void synchronize_srcu(struct srcu_struct *ssp);

		#define SRCU_GET_STATE_COMPLETED 0x1
		@@ -176,17 +183,6 @@ static inline int srcu_read_lock_held(const struct srcu_struct *ssp)

		#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */

		#define SRCU_NMI_UNKNOWN 0x0
		#define SRCU_NMI_UNSAFE 0x1
		#define SRCU_NMI_SAFE 0x2

		#if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU)
		void srcu_check_nmi_safety(struct srcu_struct *ssp, bool nmi_safe);
		#else
		static inline void srcu_check_nmi_safety(struct srcu_struct *ssp,
		bool nmi_safe) { }
		#endif


		/**
		* srcu_dereference_check - fetch SRCU-protected pointer for later dereferencing
		@@ -236,33 +232,67 @@ static inline void srcu_check_nmi_safety(struct srcu_struct *ssp,
		* a mutex that is held elsewhere while calling synchronize_srcu() or
		* synchronize_srcu_expedited().
		*
		* Note that srcu_read_lock() and the matching srcu_read_unlock() must
		* occur in the same context, for example, it is illegal to invoke
		* srcu_read_unlock() in an irq handler if the matching srcu_read_lock()
		* was invoked in process context.
		* The return value from srcu_read_lock() must be passed unaltered
		* to the matching srcu_read_unlock(). Note that srcu_read_lock() and
		* the matching srcu_read_unlock() must occur in the same context, for
		* example, it is illegal to invoke srcu_read_unlock() in an irq handler
		* if the matching srcu_read_lock() was invoked in process context. Or,
		* for that matter to invoke srcu_read_unlock() from one task and the
		* matching srcu_read_lock() from another.
		*/
		static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp)
		{
		int retval;

		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		retval = __srcu_read_lock(ssp);
		srcu_lock_acquire(&ssp->dep_map);
		return retval;
		}

		/**
		* srcu_read_lock_lite - register a new reader for an SRCU-protected structure.
		* @ssp: srcu_struct in which to register the new reader.
		*
		* Enter an SRCU read-side critical section, but for a light-weight
		* smp_mb()-free reader. See srcu_read_lock() for more information.
		*
		* If srcu_read_lock_lite() is ever used on an srcu_struct structure,
		* then none of the other flavors may be used, whether before, during,
		* or after. Note that grace-period auto-expediting is disabled for _lite
		* srcu_struct structures because auto-expedited grace periods invoke
		* synchronize_rcu_expedited(), IPIs and all.
		*
		* Note that srcu_read_lock_lite() can be invoked only from those contexts
		* where RCU is watching, that is, from contexts where it would be legal
		* to invoke rcu_read_lock(). Otherwise, lockdep will complain.
		*/
		static inline int srcu_read_lock_lite(struct srcu_struct *ssp) __acquires(ssp)
		{
		int retval;

		srcu_check_read_flavor_lite(ssp);
		retval = __srcu_read_lock_lite(ssp);
		rcu_try_lock_acquire(&ssp->dep_map);
		return retval;
		}

		/**
		* srcu_read_lock_nmisafe - register a new reader for an SRCU-protected structure.
		* @ssp: srcu_struct in which to register the new reader.
		*
		* Enter an SRCU read-side critical section, but in an NMI-safe manner.
		* See srcu_read_lock() for more information.
		*
		* If srcu_read_lock_nmisafe() is ever used on an srcu_struct structure,
		* then none of the other flavors may be used, whether before, during,
		* or after.
		*/
		static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp)
		{
		int retval;

		srcu_check_nmi_safety(ssp, true);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI);
		retval = __srcu_read_lock_nmisafe(ssp);
		rcu_try_lock_acquire(&ssp->dep_map);
		return retval;
		@@ -274,7 +304,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp)
		{
		int retval;

		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		retval = __srcu_read_lock(ssp);
		return retval;
		}
		@@ -303,7 +333,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp)
		static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp)
		{
		WARN_ON_ONCE(in_nmi());
		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		return __srcu_read_lock(ssp);
		}

		@@ -318,11 +348,27 @@ static inline void srcu_read_unlock(struct srcu_struct *ssp, int idx)
		__releases(ssp)
		{
		WARN_ON_ONCE(idx & ~0x1);
		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		srcu_lock_release(&ssp->dep_map);
		__srcu_read_unlock(ssp, idx);
		}

		/**
		* srcu_read_unlock_lite - unregister a old reader from an SRCU-protected structure.
		* @ssp: srcu_struct in which to unregister the old reader.
		* @idx: return value from corresponding srcu_read_lock().
		*
		* Exit a light-weight SRCU read-side critical section.
		*/
		static inline void srcu_read_unlock_lite(struct srcu_struct *ssp, int idx)
		__releases(ssp)
		{
		WARN_ON_ONCE(idx & ~0x1);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_LITE);
		srcu_lock_release(&ssp->dep_map);
		__srcu_read_unlock_lite(ssp, idx);
		}

		/**
		* srcu_read_unlock_nmisafe - unregister a old reader from an SRCU-protected structure.
		* @ssp: srcu_struct in which to unregister the old reader.
		@@ -334,7 +380,7 @@ static inline void srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx)
		__releases(ssp)
		{
		WARN_ON_ONCE(idx & ~0x1);
		srcu_check_nmi_safety(ssp, true);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI);
		rcu_lock_release(&ssp->dep_map);
		__srcu_read_unlock_nmisafe(ssp, idx);
		}
		@@ -343,7 +389,7 @@ static inline void srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx)
		static inline notrace void
		srcu_read_unlock_notrace(struct srcu_struct *ssp, int idx) __releases(ssp)
		{
		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		__srcu_read_unlock(ssp, idx);
		}

		@@ -360,7 +406,7 @@ static inline void srcu_up_read(struct srcu_struct *ssp, int idx)
		{
		WARN_ON_ONCE(idx & ~0x1);
		WARN_ON_ONCE(in_nmi());
		srcu_check_nmi_safety(ssp, false);
		srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL);
		__srcu_read_unlock(ssp, idx);
		}

include/linux/srcutiny.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -81,6 +81,9 @@ static inline void srcu_barrier(struct srcu_struct *ssp)
		synchronize_srcu(ssp);
		}

		#define srcu_check_read_flavor(ssp, read_flavor) do { } while (0)
		#define srcu_check_read_flavor_lite(ssp) do { } while (0)

		/* Defined here to avoid size increase for non-torture kernels. */
		static inline void srcu_torture_stats_print(struct srcu_struct *ssp,
		char tt, char tf)