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-rw-r--r--kernel/locking/Makefile9
-rw-r--r--kernel/locking/lglock.c91
-rw-r--r--kernel/locking/lockdep.c2
-rw-r--r--kernel/locking/locktorture.c1
-rw-r--r--kernel/locking/rt.c498
-rw-r--r--kernel/locking/rtmutex.c828
-rw-r--r--kernel/locking/rtmutex_common.h17
-rw-r--r--kernel/locking/spinlock.c7
-rw-r--r--kernel/locking/spinlock_debug.c5
9 files changed, 1386 insertions, 72 deletions
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 31322a4275cd..c6bba9299d8b 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -2,7 +2,7 @@
# and is generally not a function of system call inputs.
KCOV_INSTRUMENT := n
-obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
+obj-y += semaphore.o percpu-rwsem.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
@@ -11,7 +11,11 @@ CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE)
endif
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
+obj-y += mutex.o
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+obj-y += rwsem.o
+endif
obj-$(CONFIG_LOCKDEP) += lockdep.o
ifeq ($(CONFIG_PROC_FS),y)
obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
@@ -25,7 +29,10 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
+endif
+obj-$(CONFIG_PREEMPT_RT_FULL) += rt.o
obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o
obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
index 951cfcd10b4a..57e0ea72c28a 100644
--- a/kernel/locking/lglock.c
+++ b/kernel/locking/lglock.c
@@ -4,6 +4,15 @@
#include <linux/cpu.h>
#include <linux/string.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr arch_spinlock_t
+# define lg_do_lock(l) arch_spin_lock(l)
+# define lg_do_unlock(l) arch_spin_unlock(l)
+#else
+# define lg_lock_ptr struct rt_mutex
+# define lg_do_lock(l) __rt_spin_lock__no_mg(l)
+# define lg_do_unlock(l) __rt_spin_unlock(l)
+#endif
/*
* Note there is no uninit, so lglocks cannot be defined in
* modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
void lg_lock_init(struct lglock *lg, char *name)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+ rt_mutex_init(lock);
+ }
+#endif
LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
}
EXPORT_SYMBOL(lg_lock_init);
void lg_local_lock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ migrate_disable();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock);
void lg_local_unlock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ migrate_enable();
}
EXPORT_SYMBOL(lg_local_unlock);
void lg_local_lock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock_cpu);
void lg_local_unlock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
@@ -68,30 +86,30 @@ void lg_double_lock(struct lglock *lg, int cpu1, int cpu2)
if (cpu2 < cpu1)
swap(cpu1, cpu2);
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
- arch_spin_lock(per_cpu_ptr(lg->lock, cpu1));
- arch_spin_lock(per_cpu_ptr(lg->lock, cpu2));
+ lg_do_lock(per_cpu_ptr(lg->lock, cpu1));
+ lg_do_lock(per_cpu_ptr(lg->lock, cpu2));
}
void lg_double_unlock(struct lglock *lg, int cpu1, int cpu2)
{
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
- arch_spin_unlock(per_cpu_ptr(lg->lock, cpu1));
- arch_spin_unlock(per_cpu_ptr(lg->lock, cpu2));
- preempt_enable();
+ lg_do_unlock(per_cpu_ptr(lg->lock, cpu1));
+ lg_do_unlock(per_cpu_ptr(lg->lock, cpu2));
+ preempt_enable_nort();
}
void lg_global_lock(struct lglock *lg)
{
int i;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
}
EXPORT_SYMBOL(lg_global_lock);
@@ -102,10 +120,35 @@ void lg_global_unlock(struct lglock *lg)
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_unlock(lock);
+ lg_do_unlock(lock);
}
- preempt_enable();
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_global_unlock);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * HACK: If you use this, you get to keep the pieces.
+ * Used in queue_stop_cpus_work() when stop machinery
+ * is called from inactive CPU, so we can't schedule.
+ */
+# define lg_do_trylock_relax(l) \
+ do { \
+ while (!__rt_spin_trylock(l)) \
+ cpu_relax(); \
+ } while (0)
+
+void lg_global_trylock_relax(struct lglock *lg)
+{
+ int i;
+
+ lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+ for_each_possible_cpu(i) {
+ lg_lock_ptr *lock;
+ lock = per_cpu_ptr(lg->lock, i);
+ lg_do_trylock_relax(lock);
+ }
+}
+#endif
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 589d763a49b3..4b48c4bfb60c 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3686,6 +3686,7 @@ static void check_flags(unsigned long flags)
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* We dont accurately track softirq state in e.g.
* hardirq contexts (such as on 4KSTACKS), so only
@@ -3700,6 +3701,7 @@ static void check_flags(unsigned long flags)
DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
}
}
+#endif
if (!debug_locks)
print_irqtrace_events(current);
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index f8c5af52a131..788068773e61 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -26,7 +26,6 @@
#include <linux/kthread.h>
#include <linux/sched/rt.h>
#include <linux/spinlock.h>
-#include <linux/rwlock.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/smp.h>
diff --git a/kernel/locking/rt.c b/kernel/locking/rt.c
new file mode 100644
index 000000000000..665754c00e1e
--- /dev/null
+++ b/kernel/locking/rt.c
@@ -0,0 +1,498 @@
+/*
+ * kernel/rt.c
+ *
+ * Real-Time Preemption Support
+ *
+ * started by Ingo Molnar:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * historic credit for proving that Linux spinlocks can be implemented via
+ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow
+ * and others) who prototyped it on 2.4 and did lots of comparative
+ * research and analysis; TimeSys, for proving that you can implement a
+ * fully preemptible kernel via the use of IRQ threading and mutexes;
+ * Bill Huey for persuasively arguing on lkml that the mutex model is the
+ * right one; and to MontaVista, who ported pmutexes to 2.6.
+ *
+ * This code is a from-scratch implementation and is not based on pmutexes,
+ * but the idea of converting spinlocks to mutexes is used here too.
+ *
+ * lock debugging, locking tree, deadlock detection:
+ *
+ * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ * Released under the General Public License (GPL).
+ *
+ * Includes portions of the generic R/W semaphore implementation from:
+ *
+ * Copyright (c) 2001 David Howells (dhowells@redhat.com).
+ * - Derived partially from idea by Andrea Arcangeli <andrea@suse.de>
+ * - Derived also from comments by Linus
+ *
+ * Pending ownership of locks and ownership stealing:
+ *
+ * Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt
+ *
+ * (also by Steven Rostedt)
+ * - Converted single pi_lock to individual task locks.
+ *
+ * By Esben Nielsen:
+ * Doing priority inheritance with help of the scheduler.
+ *
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ * - major rework based on Esben Nielsens initial patch
+ * - replaced thread_info references by task_struct refs
+ * - removed task->pending_owner dependency
+ * - BKL drop/reacquire for semaphore style locks to avoid deadlocks
+ * in the scheduler return path as discussed with Steven Rostedt
+ *
+ * Copyright (C) 2006, Kihon Technologies Inc.
+ * Steven Rostedt <rostedt@goodmis.org>
+ * - debugged and patched Thomas Gleixner's rework.
+ * - added back the cmpxchg to the rework.
+ * - turned atomic require back on for SMP.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/futex.h>
+#include <linux/hrtimer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+ lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+ mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+ mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+ int ret = rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/*
+ * rwlock_t functions
+ */
+int __lockfunc rt_write_trylock(rwlock_t *rwlock)
+{
+ int ret;
+
+ migrate_disable();
+ ret = rt_mutex_trylock(&rwlock->lock);
+ if (ret)
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ else
+ migrate_enable();
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock);
+
+int __lockfunc rt_write_trylock_irqsave(rwlock_t *rwlock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_write_trylock(rwlock);
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock_irqsave);
+
+int __lockfunc rt_read_trylock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the lock,
+ * but not when read_depth == 0 which means that the lock is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current) {
+ migrate_disable();
+ ret = rt_mutex_trylock(lock);
+ if (ret)
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ else
+ migrate_enable();
+
+ } else if (!rwlock->read_depth) {
+ ret = 0;
+ }
+
+ if (ret)
+ rwlock->read_depth++;
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_read_trylock);
+
+void __lockfunc rt_write_lock(rwlock_t *rwlock)
+{
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ __rt_spin_lock(&rwlock->lock);
+}
+EXPORT_SYMBOL(rt_write_lock);
+
+void __lockfunc rt_read_lock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+
+
+ /*
+ * recursive read locks succeed when current owns the lock
+ */
+ if (rt_mutex_owner(lock) != current) {
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ __rt_spin_lock(lock);
+ }
+ rwlock->read_depth++;
+}
+
+EXPORT_SYMBOL(rt_read_lock);
+
+void __lockfunc rt_write_unlock(rwlock_t *rwlock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+}
+EXPORT_SYMBOL(rt_write_unlock);
+
+void __lockfunc rt_read_unlock(rwlock_t *rwlock)
+{
+ /* Release the lock only when read_depth is down to 0 */
+ if (--rwlock->read_depth == 0) {
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+ }
+}
+EXPORT_SYMBOL(rt_read_unlock);
+
+unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_write_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_write_lock_irqsave);
+
+unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_read_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_read_lock_irqsave);
+
+void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock));
+ lockdep_init_map(&rwlock->dep_map, name, key, 0);
+#endif
+ rwlock->lock.save_state = 1;
+ rwlock->read_depth = 0;
+}
+EXPORT_SYMBOL(__rt_rwlock_init);
+
+/*
+ * rw_semaphores
+ */
+
+void rt_up_write(struct rw_semaphore *rwsem)
+{
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_up_write);
+
+void __rt_up_read(struct rw_semaphore *rwsem)
+{
+ if (--rwsem->read_depth == 0)
+ rt_mutex_unlock(&rwsem->lock);
+}
+
+void rt_up_read(struct rw_semaphore *rwsem)
+{
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ __rt_up_read(rwsem);
+}
+EXPORT_SYMBOL(rt_up_read);
+
+/*
+ * downgrade a write lock into a read lock
+ * - just wake up any readers at the front of the queue
+ */
+void rt_downgrade_write(struct rw_semaphore *rwsem)
+{
+ BUG_ON(rt_mutex_owner(&rwsem->lock) != current);
+ rwsem->read_depth = 1;
+}
+EXPORT_SYMBOL(rt_downgrade_write);
+
+int rt_down_write_trylock(struct rw_semaphore *rwsem)
+{
+ int ret = rt_mutex_trylock(&rwsem->lock);
+
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_write_trylock);
+
+void rt_down_write(struct rw_semaphore *rwsem)
+{
+ rwsem_acquire(&rwsem->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write);
+
+int rt_down_write_killable(struct rw_semaphore *rwsem)
+{
+ int ret;
+
+ rwsem_acquire(&rwsem->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&rwsem->lock);
+ if (ret)
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_write_killable);
+
+int rt_down_write_killable_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ int ret;
+
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&rwsem->lock);
+ if (ret)
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_write_killable_nested);
+
+void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested);
+
+void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+ struct lockdep_map *nest)
+{
+ rwsem_acquire_nest(&rwsem->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested_lock);
+
+int rt__down_read_trylock(struct rw_semaphore *rwsem)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the rwsem,
+ * but not when read_depth == 0 which means that the rwsem is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current)
+ ret = rt_mutex_trylock(&rwsem->lock);
+ else if (!rwsem->read_depth)
+ ret = 0;
+
+ if (ret)
+ rwsem->read_depth++;
+ return ret;
+
+}
+
+int rt_down_read_trylock(struct rw_semaphore *rwsem)
+{
+ int ret;
+
+ ret = rt__down_read_trylock(rwsem);
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_read_trylock);
+
+void rt__down_read(struct rw_semaphore *rwsem)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+
+ if (rt_mutex_owner(lock) != current)
+ rt_mutex_lock(&rwsem->lock);
+ rwsem->read_depth++;
+}
+EXPORT_SYMBOL(rt__down_read);
+
+static void __rt_down_read(struct rw_semaphore *rwsem, int subclass)
+{
+ rwsem_acquire_read(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt__down_read(rwsem);
+}
+
+void rt_down_read(struct rw_semaphore *rwsem)
+{
+ __rt_down_read(rwsem, 0);
+}
+EXPORT_SYMBOL(rt_down_read);
+
+void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ __rt_down_read(rwsem, subclass);
+}
+EXPORT_SYMBOL(rt_down_read_nested);
+
+void __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwsem, sizeof(*rwsem));
+ lockdep_init_map(&rwsem->dep_map, name, key, 0);
+#endif
+ rwsem->read_depth = 0;
+ rwsem->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__rt_rwsem_init);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+ /* dec if we can't possibly hit 0 */
+ if (atomic_add_unless(cnt, -1, 1))
+ return 0;
+ /* we might hit 0, so take the lock */
+ mutex_lock(lock);
+ if (!atomic_dec_and_test(cnt)) {
+ /* when we actually did the dec, we didn't hit 0 */
+ mutex_unlock(lock);
+ return 0;
+ }
+ /* we hit 0, and we hold the lock */
+ return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 2c49d76f96c3..6f2ded470af1 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -7,6 +7,11 @@
* Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
* Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
* Copyright (C) 2006 Esben Nielsen
+ * Adaptive Spinlocks:
+ * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ * and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
*
* See Documentation/locking/rt-mutex-design.txt for details.
*/
@@ -16,6 +21,7 @@
#include <linux/sched/rt.h>
#include <linux/sched/deadline.h>
#include <linux/timer.h>
+#include <linux/ww_mutex.h>
#include "rtmutex_common.h"
@@ -133,6 +139,12 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS);
}
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+ return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+ waiter != PI_REQUEUE_INPROGRESS;
+}
+
/*
* We can speed up the acquire/release, if there's no debugging state to be
* set up.
@@ -414,6 +426,14 @@ static bool rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter,
return debug_rt_mutex_detect_deadlock(waiter, chwalk);
}
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+ if (waiter->savestate)
+ wake_up_lock_sleeper(waiter->task);
+ else
+ wake_up_process(waiter->task);
+}
+
/*
* Max number of times we'll walk the boosting chain:
*/
@@ -421,7 +441,8 @@ int max_lock_depth = 1024;
static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
{
- return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
+ return rt_mutex_real_waiter(p->pi_blocked_on) ?
+ p->pi_blocked_on->lock : NULL;
}
/*
@@ -557,7 +578,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* reached or the state of the chain has changed while we
* dropped the locks.
*/
- if (!waiter)
+ if (!rt_mutex_real_waiter(waiter))
goto out_unlock_pi;
/*
@@ -719,13 +740,16 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* follow here. This is the end of the chain we are walking.
*/
if (!rt_mutex_owner(lock)) {
+ struct rt_mutex_waiter *lock_top_waiter;
+
/*
* If the requeue [7] above changed the top waiter,
* then we need to wake the new top waiter up to try
* to get the lock.
*/
- if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
+ lock_top_waiter = rt_mutex_top_waiter(lock);
+ if (prerequeue_top_waiter != lock_top_waiter)
+ rt_mutex_wake_waiter(lock_top_waiter);
raw_spin_unlock_irq(&lock->wait_lock);
return 0;
}
@@ -818,6 +842,25 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
return ret;
}
+
+#define STEAL_NORMAL 0
+#define STEAL_LATERAL 1
+
+/*
+ * Note that RT tasks are excluded from lateral-steals to prevent the
+ * introduction of an unbounded latency
+ */
+static inline int lock_is_stealable(struct task_struct *task,
+ struct task_struct *pendowner, int mode)
+{
+ if (mode == STEAL_NORMAL || rt_task(task)) {
+ if (task->prio >= pendowner->prio)
+ return 0;
+ } else if (task->prio > pendowner->prio)
+ return 0;
+ return 1;
+}
+
/*
* Try to take an rt-mutex
*
@@ -828,8 +871,9 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* @waiter: The waiter that is queued to the lock's wait tree if the
* callsite called task_blocked_on_lock(), otherwise NULL
*/
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
+static int __try_to_take_rt_mutex(struct rt_mutex *lock,
+ struct task_struct *task,
+ struct rt_mutex_waiter *waiter, int mode)
{
/*
* Before testing whether we can acquire @lock, we set the
@@ -866,8 +910,10 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
* If waiter is not the highest priority waiter of
* @lock, give up.
*/
- if (waiter != rt_mutex_top_waiter(lock))
+ if (waiter != rt_mutex_top_waiter(lock)) {
+ /* XXX lock_is_stealable() ? */
return 0;
+ }
/*
* We can acquire the lock. Remove the waiter from the
@@ -885,14 +931,10 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
* not need to be dequeued.
*/
if (rt_mutex_has_waiters(lock)) {
- /*
- * If @task->prio is greater than or equal to
- * the top waiter priority (kernel view),
- * @task lost.
- */
- if (task->prio >= rt_mutex_top_waiter(lock)->prio)
- return 0;
+ struct task_struct *pown = rt_mutex_top_waiter(lock)->task;
+ if (task != pown && !lock_is_stealable(task, pown, mode))
+ return 0;
/*
* The current top waiter stays enqueued. We
* don't have to change anything in the lock
@@ -941,6 +983,438 @@ takeit:
return 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock,
+ bool mg_off),
+ bool do_mig_dis)
+{
+ might_sleep_no_state_check();
+
+ if (do_mig_dis)
+ migrate_disable();
+
+ if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
+ rt_mutex_deadlock_account_lock(lock, current);
+ else
+ slowfn(lock, do_mig_dis);
+}
+
+static inline int rt_spin_lock_fastunlock(struct rt_mutex *lock,
+ int (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) {
+ rt_mutex_deadlock_account_unlock(current);
+ return 0;
+ }
+ return slowfn(lock);
+}
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *owner)
+{
+ int res = 0;
+
+ rcu_read_lock();
+ for (;;) {
+ if (owner != rt_mutex_owner(lock))
+ break;
+ /*
+ * Ensure that owner->on_cpu is dereferenced _after_
+ * checking the above to be valid.
+ */
+ barrier();
+ if (!owner->on_cpu) {
+ res = 1;
+ break;
+ }
+ cpu_relax();
+ }
+ rcu_read_unlock();
+ return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *orig_owner)
+{
+ return 1;
+}
+#endif
+
+static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
+ enum rtmutex_chainwalk chwalk);
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock,
+ bool mg_off)
+{
+ struct task_struct *lock_owner, *self = current;
+ struct rt_mutex_waiter waiter, *top_waiter;
+ unsigned long flags;
+ int ret;
+
+ rt_mutex_init_waiter(&waiter, true);
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ return;
+ }
+
+ BUG_ON(rt_mutex_owner(lock) == self);
+
+ /*
+ * We save whatever state the task is in and we'll restore it
+ * after acquiring the lock taking real wakeups into account
+ * as well. We are serialized via pi_lock against wakeups. See
+ * try_to_wake_up().
+ */
+ raw_spin_lock(&self->pi_lock);
+ self->saved_state = self->state;
+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+ raw_spin_unlock(&self->pi_lock);
+
+ ret = task_blocks_on_rt_mutex(lock, &waiter, self, RT_MUTEX_MIN_CHAINWALK);
+ BUG_ON(ret);
+
+ for (;;) {
+ /* Try to acquire the lock again. */
+ if (__try_to_take_rt_mutex(lock, self, &waiter, STEAL_LATERAL))
+ break;
+
+ top_waiter = rt_mutex_top_waiter(lock);
+ lock_owner = rt_mutex_owner(lock);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+ debug_rt_mutex_print_deadlock(&waiter);
+
+ if (top_waiter != &waiter || adaptive_wait(lock, lock_owner)) {
+ if (mg_off)
+ migrate_enable();
+ schedule();
+ if (mg_off)
+ migrate_disable();
+ }
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ raw_spin_lock(&self->pi_lock);
+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+ raw_spin_unlock(&self->pi_lock);
+ }
+
+ /*
+ * Restore the task state to current->saved_state. We set it
+ * to the original state above and the try_to_wake_up() code
+ * has possibly updated it when a real (non-rtmutex) wakeup
+ * happened while we were blocked. Clear saved_state so
+ * try_to_wakeup() does not get confused.
+ */
+ raw_spin_lock(&self->pi_lock);
+ __set_current_state_no_track(self->saved_state);
+ self->saved_state = TASK_RUNNING;
+ raw_spin_unlock(&self->pi_lock);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up:
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
+ BUG_ON(!RB_EMPTY_NODE(&waiter.tree_entry));
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+ debug_rt_mutex_free_waiter(&waiter);
+}
+
+static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q,
+ struct rt_mutex *lock);
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+static int noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ unsigned long flags;
+ WAKE_Q(wake_q);
+ WAKE_Q(wake_sleeper_q);
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ return 0;
+ }
+
+ mark_wakeup_next_waiter(&wake_q, &wake_sleeper_q, lock);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ wake_up_q(&wake_q);
+ wake_up_q_sleeper(&wake_sleeper_q);
+
+ /* Undo pi boosting.when necessary */
+ rt_mutex_adjust_prio(current);
+ return 0;
+}
+
+static int noinline __sched rt_spin_lock_slowunlock_no_deboost(struct rt_mutex *lock)
+{
+ unsigned long flags;
+ WAKE_Q(wake_q);
+ WAKE_Q(wake_sleeper_q);
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ return 0;
+ }
+
+ mark_wakeup_next_waiter(&wake_q, &wake_sleeper_q, lock);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ wake_up_q(&wake_q);
+ wake_up_q_sleeper(&wake_sleeper_q);
+ return 1;
+}
+
+void __lockfunc rt_spin_lock__no_mg(spinlock_t *lock)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock, false);
+ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock__no_mg);
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock, true);
+ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock, true);
+}
+EXPORT_SYMBOL(__rt_spin_lock);
+
+void __lockfunc __rt_spin_lock__no_mg(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock, false);
+}
+EXPORT_SYMBOL(__rt_spin_lock__no_mg);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+ spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock, true);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock__no_mg(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(rt_spin_unlock__no_mg);
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+ migrate_enable();
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+int __lockfunc rt_spin_unlock_no_deboost(spinlock_t *lock)
+{
+ int ret;
+
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ ret = rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_no_deboost);
+ migrate_enable();
+ return ret;
+}
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+ spin_lock(lock);
+ spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc __rt_spin_trylock(struct rt_mutex *lock)
+{
+ return rt_mutex_trylock(lock);
+}
+
+int __lockfunc rt_spin_trylock__no_mg(spinlock_t *lock)
+{
+ int ret;
+
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret)
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock__no_mg);
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+ int ret;
+
+ migrate_disable();
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret)
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ else
+ migrate_enable();
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ } else
+ local_bh_enable();
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+ rt_spin_lock(lock);
+ if (atomic_dec_and_test(atomic))
+ return 1;
+ rt_spin_unlock(lock);
+ return 0;
+}
+EXPORT_SYMBOL(atomic_dec_and_spin_lock);
+
+ void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct ww_acquire_ctx *hold_ctx = ACCESS_ONCE(ww->ctx);
+
+ if (!hold_ctx)
+ return 0;
+
+ if (unlikely(ctx == hold_ctx))
+ return -EALREADY;
+
+ if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+ (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+ ctx->contending_lock = ww;
+#endif
+ return -EDEADLK;
+ }
+
+ return 0;
+}
+#else
+ static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ BUG();
+ return 0;
+}
+
+#endif
+
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter)
+{
+ return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
/*
* Task blocks on lock.
*
@@ -971,6 +1445,23 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
return -EDEADLK;
raw_spin_lock(&task->pi_lock);
+
+ /*
+ * In the case of futex requeue PI, this will be a proxy
+ * lock. The task will wake unaware that it is enqueueed on
+ * this lock. Avoid blocking on two locks and corrupting
+ * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+ * flag. futex_wait_requeue_pi() sets this when it wakes up
+ * before requeue (due to a signal or timeout). Do not enqueue
+ * the task if PI_WAKEUP_INPROGRESS is set.
+ */
+ if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+ raw_spin_unlock(&task->pi_lock);
+ return -EAGAIN;
+ }
+
+ BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
__rt_mutex_adjust_prio(task);
waiter->task = task;
waiter->lock = lock;
@@ -994,7 +1485,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
rt_mutex_enqueue_pi(owner, waiter);
__rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
} else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) {
chain_walk = 1;
@@ -1036,6 +1527,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
* Called with lock->wait_lock held and interrupts disabled.
*/
static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q,
struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
@@ -1064,7 +1556,10 @@ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
raw_spin_unlock(&current->pi_lock);
- wake_q_add(wake_q, waiter->task);
+ if (waiter->savestate)
+ wake_q_add(wake_sleeper_q, waiter->task);
+ else
+ wake_q_add(wake_q, waiter->task);
}
/*
@@ -1078,7 +1573,7 @@ static void remove_waiter(struct rt_mutex *lock,
{
bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
- struct rt_mutex *next_lock;
+ struct rt_mutex *next_lock = NULL;
raw_spin_lock(&current->pi_lock);
rt_mutex_dequeue(lock, waiter);
@@ -1102,7 +1597,8 @@ static void remove_waiter(struct rt_mutex *lock,
__rt_mutex_adjust_prio(owner);
/* Store the lock on which owner is blocked or NULL */
- next_lock = task_blocked_on_lock(owner);
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
+ next_lock = task_blocked_on_lock(owner);
raw_spin_unlock(&owner->pi_lock);
@@ -1138,17 +1634,17 @@ void rt_mutex_adjust_pi(struct task_struct *task)
raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
- if (!waiter || (waiter->prio == task->prio &&
+ if (!rt_mutex_real_waiter(waiter) || (waiter->prio == task->prio &&
!dl_prio(task->prio))) {
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return;
}
next_lock = waiter->lock;
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
next_lock, NULL, task);
}
@@ -1166,7 +1662,8 @@ void rt_mutex_adjust_pi(struct task_struct *task)
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct ww_acquire_ctx *ww_ctx)
{
int ret = 0;
@@ -1189,6 +1686,12 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
break;
}
+ if (ww_ctx && ww_ctx->acquired > 0) {
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ if (ret)
+ break;
+ }
+
raw_spin_unlock_irq(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
@@ -1223,21 +1726,96 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
}
}
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+ struct ww_acquire_ctx *ww_ctx)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+ /*
+ * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+ * but released with a normal mutex_unlock in this call.
+ *
+ * This should never happen, always use ww_mutex_unlock.
+ */
+ DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+ /*
+ * Not quite done after calling ww_acquire_done() ?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
+
+ if (ww_ctx->contending_lock) {
+ /*
+ * After -EDEADLK you tried to
+ * acquire a different ww_mutex? Bad!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+ /*
+ * You called ww_mutex_lock after receiving -EDEADLK,
+ * but 'forgot' to unlock everything else first?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+ ww_ctx->contending_lock = NULL;
+ }
+
+ /*
+ * Naughty, using a different class will lead to undefined behavior!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+ ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct rt_mutex_waiter *waiter, *n;
+
+ /*
+ * This branch gets optimized out for the common case,
+ * and is only important for ww_mutex_lock.
+ */
+ ww_mutex_lock_acquired(ww, ww_ctx);
+ ww->ctx = ww_ctx;
+
+ /*
+ * Give any possible sleeping processes the chance to wake up,
+ * so they can recheck if they have to back off.
+ */
+ rbtree_postorder_for_each_entry_safe(waiter, n, &lock->waiters,
+ tree_entry) {
+ /* XXX debug rt mutex waiter wakeup */
+
+ BUG_ON(waiter->lock != lock);
+ rt_mutex_wake_waiter(waiter);
+ }
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ BUG();
+}
+#endif
+
/*
* Slow path lock function:
*/
static int __sched
rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk)
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;
unsigned long flags;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
- RB_CLEAR_NODE(&waiter.pi_tree_entry);
- RB_CLEAR_NODE(&waiter.tree_entry);
+ rt_mutex_init_waiter(&waiter, false);
/*
* Technically we could use raw_spin_[un]lock_irq() here, but this can
@@ -1251,6 +1829,8 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
+ if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return 0;
}
@@ -1265,13 +1845,23 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
if (likely(!ret))
/* sleep on the mutex */
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter,
+ ww_ctx);
+ else if (ww_ctx) {
+ /* ww_mutex received EDEADLK, let it become EALREADY */
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ BUG_ON(!ret);
+ }
if (unlikely(ret)) {
__set_current_state(TASK_RUNNING);
if (rt_mutex_has_waiters(lock))
remove_waiter(lock, &waiter);
- rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+ /* ww_mutex want to report EDEADLK/EALREADY, let them */
+ if (!ww_ctx)
+ rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+ } else if (ww_ctx) {
+ ww_mutex_account_lock(lock, ww_ctx);
}
/*
@@ -1331,7 +1921,8 @@ static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
* Return whether the current task needs to undo a potential priority boosting.
*/
static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
- struct wake_q_head *wake_q)
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q)
{
unsigned long flags;
@@ -1387,7 +1978,7 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
*
* Queue the next waiter for wakeup once we release the wait_lock.
*/
- mark_wakeup_next_waiter(wake_q, lock);
+ mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
@@ -1403,31 +1994,36 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
+ return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK,
+ ww_ctx);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, timeout, chwalk);
+ return slowfn(lock, state, timeout, chwalk, ww_ctx);
}
static inline int
@@ -1444,17 +2040,20 @@ rt_mutex_fasttrylock(struct rt_mutex *lock,
static inline void
rt_mutex_fastunlock(struct rt_mutex *lock,
bool (*slowfn)(struct rt_mutex *lock,
- struct wake_q_head *wqh))
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper))
{
WAKE_Q(wake_q);
+ WAKE_Q(wake_sleeper_q);
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) {
rt_mutex_deadlock_account_unlock(current);
} else {
- bool deboost = slowfn(lock, &wake_q);
+ bool deboost = slowfn(lock, &wake_q, &wake_sleeper_q);
wake_up_q(&wake_q);
+ wake_up_q_sleeper(&wake_sleeper_q);
/* Undo pi boosting if necessary: */
if (deboost)
@@ -1471,7 +2070,7 @@ void __sched rt_mutex_lock(struct rt_mutex *lock)
{
might_sleep();
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+ rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
@@ -1488,7 +2087,7 @@ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
might_sleep();
- return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
+ return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
@@ -1501,11 +2100,30 @@ int rt_mutex_timed_futex_lock(struct rt_mutex *lock,
might_sleep();
return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
- RT_MUTEX_FULL_CHAINWALK,
+ RT_MUTEX_FULL_CHAINWALK, NULL,
rt_mutex_slowlock);
}
/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+ might_sleep();
+
+ return rt_mutex_fastlock(lock, TASK_KILLABLE, NULL, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
@@ -1525,6 +2143,7 @@ rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout)
return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
RT_MUTEX_MIN_CHAINWALK,
+ NULL,
rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
@@ -1542,7 +2161,11 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
*/
int __sched rt_mutex_trylock(struct rt_mutex *lock)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (WARN_ON_ONCE(in_irq() || in_nmi()))
+#else
if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
+#endif
return 0;
return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
@@ -1568,13 +2191,14 @@ EXPORT_SYMBOL_GPL(rt_mutex_unlock);
* required or not.
*/
bool __sched rt_mutex_futex_unlock(struct rt_mutex *lock,
- struct wake_q_head *wqh)
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper)
{
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) {
rt_mutex_deadlock_account_unlock(current);
return false;
}
- return rt_mutex_slowunlock(lock, wqh);
+ return rt_mutex_slowunlock(lock, wqh, wq_sleeper);
}
/**
@@ -1607,13 +2231,12 @@ EXPORT_SYMBOL_GPL(rt_mutex_destroy);
void __rt_mutex_init(struct rt_mutex *lock, const char *name)
{
lock->owner = NULL;
- raw_spin_lock_init(&lock->wait_lock);
lock->waiters = RB_ROOT;
lock->waiters_leftmost = NULL;
debug_rt_mutex_init(lock, name);
}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
/**
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1628,7 +2251,7 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init);
void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
- __rt_mutex_init(lock, NULL);
+ rt_mutex_init(lock);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
rt_mutex_deadlock_account_lock(lock, proxy_owner);
@@ -1676,6 +2299,35 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
return 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * In PREEMPT_RT there's an added race.
+ * If the task, that we are about to requeue, times out,
+ * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+ * to skip this task. But right after the task sets
+ * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+ * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+ * This will replace the PI_WAKEUP_INPROGRESS with the actual
+ * lock that it blocks on. We *must not* place this task
+ * on this proxy lock in that case.
+ *
+ * To prevent this race, we first take the task's pi_lock
+ * and check if it has updated its pi_blocked_on. If it has,
+ * we assume that it woke up and we return -EAGAIN.
+ * Otherwise, we set the task's pi_blocked_on to
+ * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+ * it will know that we are in the process of requeuing it.
+ */
+ raw_spin_lock(&task->pi_lock);
+ if (task->pi_blocked_on) {
+ raw_spin_unlock(&task->pi_lock);
+ raw_spin_unlock_irq(&lock->wait_lock);
+ return -EAGAIN;
+ }
+ task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+ raw_spin_unlock(&task->pi_lock);
+#endif
+
/* We enforce deadlock detection for futexes */
ret = task_blocks_on_rt_mutex(lock, waiter, task,
RT_MUTEX_FULL_CHAINWALK);
@@ -1690,7 +2342,7 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
ret = 0;
}
- if (unlikely(ret))
+ if (ret && rt_mutex_has_waiters(lock))
remove_waiter(lock, waiter);
raw_spin_unlock_irq(&lock->wait_lock);
@@ -1746,7 +2398,7 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
set_current_state(TASK_INTERRUPTIBLE);
/* sleep on the mutex */
- ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
if (unlikely(ret))
remove_waiter(lock, waiter);
@@ -1761,3 +2413,89 @@ int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
return ret;
}
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+ unsigned tmp;
+
+ if (ctx->deadlock_inject_countdown-- == 0) {
+ tmp = ctx->deadlock_inject_interval;
+ if (tmp > UINT_MAX/4)
+ tmp = UINT_MAX;
+ else
+ tmp = tmp*2 + tmp + tmp/2;
+
+ ctx->deadlock_inject_interval = tmp;
+ ctx->deadlock_inject_countdown = tmp;
+ ctx->contending_lock = lock;
+
+ ww_mutex_unlock(lock);
+
+ return -EDEADLK;
+ }
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);
+
+int __sched
+__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+ int nest = !!lock->ctx;
+
+ /*
+ * The unlocking fastpath is the 0->1 transition from 'locked'
+ * into 'unlocked' state:
+ */
+ if (nest) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+ if (lock->ctx->acquired > 0)
+ lock->ctx->acquired--;
+ lock->ctx = NULL;
+ }
+
+ mutex_release(&lock->base.dep_map, nest, _RET_IP_);
+ rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+#endif
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h
index e317e1cbb3eb..f457c7574920 100644
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -27,6 +27,7 @@ struct rt_mutex_waiter {
struct rb_node pi_tree_entry;
struct task_struct *task;
struct rt_mutex *lock;
+ bool savestate;
#ifdef CONFIG_DEBUG_RT_MUTEXES
unsigned long ip;
struct pid *deadlock_task_pid;
@@ -98,6 +99,9 @@ enum rtmutex_chainwalk {
/*
* PI-futex support (proxy locking functions, etc.):
*/
+#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1)
+#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2)
+
extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
@@ -111,7 +115,8 @@ extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter);
extern int rt_mutex_timed_futex_lock(struct rt_mutex *l, struct hrtimer_sleeper *to);
extern bool rt_mutex_futex_unlock(struct rt_mutex *lock,
- struct wake_q_head *wqh);
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper);
extern void rt_mutex_adjust_prio(struct task_struct *task);
#ifdef CONFIG_DEBUG_RT_MUTEXES
@@ -120,4 +125,14 @@ extern void rt_mutex_adjust_prio(struct task_struct *task);
# include "rtmutex.h"
#endif
+static inline void
+rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
+{
+ debug_rt_mutex_init_waiter(waiter);
+ waiter->task = NULL;
+ waiter->savestate = savestate;
+ RB_CLEAR_NODE(&waiter->pi_tree_entry);
+ RB_CLEAR_NODE(&waiter->tree_entry);
+}
+
#endif
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c
index db3ccb1dd614..909779647bd1 100644
--- a/kernel/locking/spinlock.c
+++ b/kernel/locking/spinlock.c
@@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
* __[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, raw_spinlock);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
+#endif
#endif
@@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
EXPORT_SYMBOL(_raw_spin_unlock_bh);
#endif
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#ifndef CONFIG_INLINE_READ_TRYLOCK
int __lockfunc _raw_read_trylock(rwlock_t *lock)
{
@@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
EXPORT_SYMBOL(_raw_write_unlock_bh);
#endif
+#endif /* !PREEMPT_RT_FULL */
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c
index 0374a596cffa..94970338d518 100644
--- a/kernel/locking/spinlock_debug.c
+++ b/kernel/locking/spinlock_debug.c
@@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
EXPORT_SYMBOL(__raw_spin_lock_init);
+#ifndef CONFIG_PREEMPT_RT_FULL
void __rwlock_init(rwlock_t *lock, const char *name,
struct lock_class_key *key)
{
@@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name,
}
EXPORT_SYMBOL(__rwlock_init);
+#endif
static void spin_dump(raw_spinlock_t *lock, const char *msg)
{
@@ -159,6 +161,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock)
arch_spin_unlock(&lock->raw_lock);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
static void rwlock_bug(rwlock_t *lock, const char *msg)
{
if (!debug_locks_off())
@@ -300,3 +303,5 @@ void do_raw_write_unlock(rwlock_t *lock)
debug_write_unlock(lock);
arch_write_unlock(&lock->raw_lock);
}
+
+#endif