Commit 207fb8c3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - a big round of FUTEX_UNLOCK_PI improvements, fixes, cleanups and
     general restructuring

   - lockdep updates such as new checks for lock_downgrade()

   - introduce the new atomic_try_cmpxchg() locking API and use it to
     optimize refcount code generation

   - ... plus misc fixes, updates and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
  MAINTAINERS: Add FUTEX SUBSYSTEM
  futex: Clarify mark_wake_futex memory barrier usage
  futex: Fix small (and harmless looking) inconsistencies
  futex: Avoid freeing an active timer
  rtmutex: Plug preempt count leak in rt_mutex_futex_unlock()
  rtmutex: Fix more prio comparisons
  rtmutex: Fix PI chain order integrity
  sched,tracing: Update trace_sched_pi_setprio()
  sched/rtmutex: Refactor rt_mutex_setprio()
  rtmutex: Clean up
  sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update
  sched/rtmutex/deadline: Fix a PI crash for deadline tasks
  rtmutex: Deboost before waking up the top waiter
  locking/ww-mutex: Limit stress test to 2 seconds
  locking/atomic: Fix atomic_try_cmpxchg() semantics
  lockdep: Fix per-cpu static objects
  futex: Drop hb->lock before enqueueing on the rtmutex
  futex: Futex_unlock_pi() determinism
  futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()
  futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()
  ...
parents 3527d3e9 59cd42c2

MAINTAINERS

+17 −0
Original line number Diff line number Diff line
@@ -5415,6 +5415,23 @@ F: fs/fuse/ 
F:	include/uapi/linux/fuse.h

F:	Documentation/filesystems/fuse.txt



FUTEX SUBSYSTEM

M:	Thomas Gleixner <tglx@linutronix.de>

M:	Ingo Molnar <mingo@redhat.com>

R:	Peter Zijlstra <peterz@infradead.org>

R:	Darren Hart <dvhart@infradead.org>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core

S:	Maintained

F:	kernel/futex.c

F:	kernel/futex_compat.c

F:	include/asm-generic/futex.h

F:	include/linux/futex.h

F:	include/uapi/linux/futex.h

F:	tools/testing/selftests/futex/

F:	tools/perf/bench/futex*

F:	Documentation/*futex*



FUTURE DOMAIN TMC-16x0 SCSI DRIVER (16-bit)

M:	Rik Faith <faith@cs.unc.edu>

L:	linux-scsi@vger.kernel.org

arch/x86/include/asm/atomic.h

+15 −18
Original line number Diff line number Diff line
@@ -186,6 +186,12 @@ static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new) 
	return cmpxchg(&v->counter, old, new);

}



#define atomic_try_cmpxchg atomic_try_cmpxchg

static __always_inline bool atomic_try_cmpxchg(atomic_t *v, int *old, int new)

{

	return try_cmpxchg(&v->counter, old, new);

}



static inline int atomic_xchg(atomic_t *v, int new)

{

	return xchg(&v->counter, new);
@@ -203,14 +209,10 @@ static inline void atomic_##op(int i, atomic_t *v) \ 
#define ATOMIC_FETCH_OP(op, c_op)					\

static inline int atomic_fetch_##op(int i, atomic_t *v)			\

{									\

	int old, val = atomic_read(v);					\

	for (;;) {							\

		old = atomic_cmpxchg(v, val, val c_op i);		\

		if (old == val)						\

			break;						\

		val = old;						\

	}								\

	return old;							\

	int val = atomic_read(v);					\

	do {								\

	} while (!atomic_try_cmpxchg(v, &val, val c_op i));		\

	return val;							\

}



#define ATOMIC_OPS(op, c_op)						\
@@ -236,16 +238,11 @@ ATOMIC_OPS(xor, ^) 
 */

static __always_inline int __atomic_add_unless(atomic_t *v, int a, int u)

{

	int c, old;

	c = atomic_read(v);

	for (;;) {

		if (unlikely(c == (u)))

	int c = atomic_read(v);

	do {

		if (unlikely(c == u))

			break;

		old = atomic_cmpxchg((v), c, c + (a));

		if (likely(old == c))

			break;

		c = old;

	}

	} while (!atomic_try_cmpxchg(v, &c, c + a));

	return c;

}

arch/x86/include/asm/atomic64_64.h

+19 −27
Original line number Diff line number Diff line
@@ -176,6 +176,12 @@ static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new) 
	return cmpxchg(&v->counter, old, new);

}



#define atomic64_try_cmpxchg atomic64_try_cmpxchg

static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, long *old, long new)

{

	return try_cmpxchg(&v->counter, old, new);

}



static inline long atomic64_xchg(atomic64_t *v, long new)

{

	return xchg(&v->counter, new);
@@ -192,17 +198,12 @@ static inline long atomic64_xchg(atomic64_t *v, long new) 
 */

static inline bool atomic64_add_unless(atomic64_t *v, long a, long u)

{

	long c, old;

	c = atomic64_read(v);

	for (;;) {

		if (unlikely(c == (u)))

			break;

		old = atomic64_cmpxchg((v), c, c + (a));

		if (likely(old == c))

			break;

		c = old;

	}

	return c != (u);

	long c = atomic64_read(v);

	do {

		if (unlikely(c == u))

			return false;

	} while (!atomic64_try_cmpxchg(v, &c, c + a));

	return true;

}



#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
@@ -216,17 +217,12 @@ static inline bool atomic64_add_unless(atomic64_t *v, long a, long u) 
 */

static inline long atomic64_dec_if_positive(atomic64_t *v)

{

	long c, old, dec;

	c = atomic64_read(v);

	for (;;) {

	long dec, c = atomic64_read(v);

	do {

		dec = c - 1;

		if (unlikely(dec < 0))

			break;

		old = atomic64_cmpxchg((v), c, dec);

		if (likely(old == c))

			break;

		c = old;

	}

	} while (!atomic64_try_cmpxchg(v, &c, dec));

	return dec;

}
@@ -242,14 +238,10 @@ static inline void atomic64_##op(long i, atomic64_t *v) \ 
#define ATOMIC64_FETCH_OP(op, c_op)					\

static inline long atomic64_fetch_##op(long i, atomic64_t *v)		\

{									\

	long old, val = atomic64_read(v);				\

	for (;;) {							\

		old = atomic64_cmpxchg(v, val, val c_op i);		\

		if (old == val)						\

			break;						\

		val = old;						\

	}								\

	return old;							\

	long val = atomic64_read(v);					\

	do {								\

	} while (!atomic64_try_cmpxchg(v, &val, val c_op i));		\

	return val;							\

}



#define ATOMIC64_OPS(op, c_op)						\

arch/x86/include/asm/cmpxchg.h

+70 −0
Original line number Diff line number Diff line
@@ -153,6 +153,76 @@ extern void __add_wrong_size(void) 
#define cmpxchg_local(ptr, old, new)					\

	__cmpxchg_local(ptr, old, new, sizeof(*(ptr)))





#define __raw_try_cmpxchg(_ptr, _pold, _new, size, lock)		\

({									\

	bool success;							\

	__typeof__(_ptr) _old = (_pold);				\

	__typeof__(*(_ptr)) __old = *_old;				\

	__typeof__(*(_ptr)) __new = (_new);				\

	switch (size) {							\

	case __X86_CASE_B:						\

	{								\

		volatile u8 *__ptr = (volatile u8 *)(_ptr);		\

		asm volatile(lock "cmpxchgb %[new], %[ptr]"		\

			     CC_SET(z)					\

			     : CC_OUT(z) (success),			\

			       [ptr] "+m" (*__ptr),			\

			       [old] "+a" (__old)			\

			     : [new] "q" (__new)			\

			     : "memory");				\

		break;							\

	}								\

	case __X86_CASE_W:						\

	{								\

		volatile u16 *__ptr = (volatile u16 *)(_ptr);		\

		asm volatile(lock "cmpxchgw %[new], %[ptr]"		\

			     CC_SET(z)					\

			     : CC_OUT(z) (success),			\

			       [ptr] "+m" (*__ptr),			\

			       [old] "+a" (__old)			\

			     : [new] "r" (__new)			\

			     : "memory");				\

		break;							\

	}								\

	case __X86_CASE_L:						\

	{								\

		volatile u32 *__ptr = (volatile u32 *)(_ptr);		\

		asm volatile(lock "cmpxchgl %[new], %[ptr]"		\

			     CC_SET(z)					\

			     : CC_OUT(z) (success),			\

			       [ptr] "+m" (*__ptr),			\

			       [old] "+a" (__old)			\

			     : [new] "r" (__new)			\

			     : "memory");				\

		break;							\

	}								\

	case __X86_CASE_Q:						\

	{								\

		volatile u64 *__ptr = (volatile u64 *)(_ptr);		\

		asm volatile(lock "cmpxchgq %[new], %[ptr]"		\

			     CC_SET(z)					\

			     : CC_OUT(z) (success),			\

			       [ptr] "+m" (*__ptr),			\

			       [old] "+a" (__old)			\

			     : [new] "r" (__new)			\

			     : "memory");				\

		break;							\

	}								\

	default:							\

		__cmpxchg_wrong_size();					\

	}								\

	if (unlikely(!success))						\

		*_old = __old;						\

	likely(success);						\

})



#define __try_cmpxchg(ptr, pold, new, size)				\

	__raw_try_cmpxchg((ptr), (pold), (new), (size), LOCK_PREFIX)



#define try_cmpxchg(ptr, pold, new)					\

	__try_cmpxchg((ptr), (pold), (new), sizeof(*(ptr)))



/*

 * xadd() adds "inc" to "*ptr" and atomically returns the previous

 * value of "*ptr".

include/linux/atomic.h

+46 −0
Original line number Diff line number Diff line
@@ -423,6 +423,29 @@ 
#endif

#endif /* atomic_cmpxchg_relaxed */



#ifndef atomic_try_cmpxchg



#define __atomic_try_cmpxchg(type, _p, _po, _n)				\

({									\

	typeof(_po) __po = (_po);					\

	typeof(*(_po)) __r, __o = *__po;				\

	__r = atomic_cmpxchg##type((_p), __o, (_n));			\

	if (unlikely(__r != __o))					\

		*__po = __r;						\

	likely(__r == __o);						\

})



#define atomic_try_cmpxchg(_p, _po, _n)		__atomic_try_cmpxchg(, _p, _po, _n)

#define atomic_try_cmpxchg_relaxed(_p, _po, _n)	__atomic_try_cmpxchg(_relaxed, _p, _po, _n)

#define atomic_try_cmpxchg_acquire(_p, _po, _n)	__atomic_try_cmpxchg(_acquire, _p, _po, _n)

#define atomic_try_cmpxchg_release(_p, _po, _n)	__atomic_try_cmpxchg(_release, _p, _po, _n)



#else /* atomic_try_cmpxchg */

#define atomic_try_cmpxchg_relaxed	atomic_try_cmpxchg

#define atomic_try_cmpxchg_acquire	atomic_try_cmpxchg

#define atomic_try_cmpxchg_release	atomic_try_cmpxchg

#endif /* atomic_try_cmpxchg */



/* cmpxchg_relaxed */

#ifndef cmpxchg_relaxed

#define  cmpxchg_relaxed		cmpxchg
@@ -996,6 +1019,29 @@ static inline int atomic_dec_if_positive(atomic_t *v) 
#endif

#endif /* atomic64_cmpxchg_relaxed */



#ifndef atomic64_try_cmpxchg



#define __atomic64_try_cmpxchg(type, _p, _po, _n)			\

({									\

	typeof(_po) __po = (_po);					\

	typeof(*(_po)) __r, __o = *__po;				\

	__r = atomic64_cmpxchg##type((_p), __o, (_n));			\

	if (unlikely(__r != __o))					\

		*__po = __r;						\

	likely(__r == __o);						\

})



#define atomic64_try_cmpxchg(_p, _po, _n)		__atomic64_try_cmpxchg(, _p, _po, _n)

#define atomic64_try_cmpxchg_relaxed(_p, _po, _n)	__atomic64_try_cmpxchg(_relaxed, _p, _po, _n)

#define atomic64_try_cmpxchg_acquire(_p, _po, _n)	__atomic64_try_cmpxchg(_acquire, _p, _po, _n)

#define atomic64_try_cmpxchg_release(_p, _po, _n)	__atomic64_try_cmpxchg(_release, _p, _po, _n)



#else /* atomic64_try_cmpxchg */

#define atomic64_try_cmpxchg_relaxed	atomic64_try_cmpxchg

#define atomic64_try_cmpxchg_acquire	atomic64_try_cmpxchg

#define atomic64_try_cmpxchg_release	atomic64_try_cmpxchg

#endif /* atomic64_try_cmpxchg */



#ifndef atomic64_andnot

static inline void atomic64_andnot(long long i, atomic64_t *v)

{

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