mirror of
https://git.proxmox.com/git/mirror_ubuntu-kernels.git
synced 2025-11-07 09:54:19 +00:00
6d41c675a5
The rtmutex specific deadlock detector predates lockdep coverage of rtmutex
and since commit f5694788ad ("rt_mutex: Add lockdep annotations") it
contains a lot of redundant functionality:
- lockdep will detect an potential deadlock before rtmutex-debug
has a chance to do so
- the deadlock debugging is restricted to rtmutexes which are not
associated to futexes and have an active waiter, which is covered by
lockdep already
Remove the redundant functionality and move actual deadlock WARN() into the
deadlock code path. The latter needs a seperate cleanup.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210326153943.320398604@linutronix.de
113 lines
3.1 KiB
C
113 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* RT Mutexes: blocking mutual exclusion locks with PI support
|
|
*
|
|
* started by Ingo Molnar and Thomas Gleixner:
|
|
*
|
|
* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
|
|
* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
|
|
*
|
|
* This file contains the public data structure and API definitions.
|
|
*/
|
|
|
|
#ifndef __LINUX_RT_MUTEX_H
|
|
#define __LINUX_RT_MUTEX_H
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/rbtree.h>
|
|
#include <linux/spinlock_types.h>
|
|
|
|
extern int max_lock_depth; /* for sysctl */
|
|
|
|
/**
|
|
* The rt_mutex structure
|
|
*
|
|
* @wait_lock: spinlock to protect the structure
|
|
* @waiters: rbtree root to enqueue waiters in priority order;
|
|
* caches top-waiter (leftmost node).
|
|
* @owner: the mutex owner
|
|
*/
|
|
struct rt_mutex {
|
|
raw_spinlock_t wait_lock;
|
|
struct rb_root_cached waiters;
|
|
struct task_struct *owner;
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
struct lockdep_map dep_map;
|
|
#endif
|
|
};
|
|
|
|
struct rt_mutex_waiter;
|
|
struct hrtimer_sleeper;
|
|
|
|
#ifdef CONFIG_DEBUG_RT_MUTEXES
|
|
extern int rt_mutex_debug_check_no_locks_freed(const void *from,
|
|
unsigned long len);
|
|
extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
|
|
#else
|
|
static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
|
|
unsigned long len)
|
|
{
|
|
return 0;
|
|
}
|
|
# define rt_mutex_debug_check_no_locks_held(task) do { } while (0)
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUG_RT_MUTEXES
|
|
|
|
# define rt_mutex_init(mutex) \
|
|
do { \
|
|
static struct lock_class_key __key; \
|
|
__rt_mutex_init(mutex, __func__, &__key); \
|
|
} while (0)
|
|
|
|
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
|
|
#else
|
|
# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL, NULL)
|
|
# define rt_mutex_debug_task_free(t) do { } while (0)
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
|
|
, .dep_map = { .name = #mutexname }
|
|
#else
|
|
#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
|
|
#endif
|
|
|
|
#define __RT_MUTEX_INITIALIZER(mutexname) \
|
|
{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
|
|
, .waiters = RB_ROOT_CACHED \
|
|
, .owner = NULL \
|
|
__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
|
|
|
|
#define DEFINE_RT_MUTEX(mutexname) \
|
|
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
|
|
|
|
/**
|
|
* rt_mutex_is_locked - is the mutex locked
|
|
* @lock: the mutex to be queried
|
|
*
|
|
* Returns 1 if the mutex is locked, 0 if unlocked.
|
|
*/
|
|
static inline int rt_mutex_is_locked(struct rt_mutex *lock)
|
|
{
|
|
return lock->owner != NULL;
|
|
}
|
|
|
|
extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
|
|
extern void rt_mutex_destroy(struct rt_mutex *lock);
|
|
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
|
|
#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
|
|
#else
|
|
extern void rt_mutex_lock(struct rt_mutex *lock);
|
|
#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
|
|
#endif
|
|
|
|
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
|
|
extern int rt_mutex_trylock(struct rt_mutex *lock);
|
|
|
|
extern void rt_mutex_unlock(struct rt_mutex *lock);
|
|
|
|
#endif
|