[patch 36/50] locking/mutex: Replace struct mutex in core code

From: Thomas Gleixner
Date: Tue Jul 13 2021 - 12:14:39 EST

Next message: Thomas Gleixner: "[patch 37/50] locking/mutex: Rearrange items in mutex.h"
Previous message: Thomas Gleixner: "[patch 35/50] locking/ww_mutex: Switch to _mutex_t"
In reply to: Thomas Gleixner: "[patch 35/50] locking/ww_mutex: Switch to _mutex_t"
Next in thread: Thomas Gleixner: "[patch 37/50] locking/mutex: Rearrange items in mutex.h"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

PREEMPT_RT replaces 'struct mutex' with a rtmutex based variant so all
mutex operations are included into the priority inheritance scheme, but
wants to utilize the ww_mutex specific part of the regular mutex
implementation as is.

As the regular mutex and ww_mutex implementation are tightly coupled
(ww_mutex has a 'struct mutex' inside) and share a lot of code (ww_mutex is
mostly an extension) a simple replacement of 'struct mutex' does not work.

'struct mutex' has a typedef '_mutex_t' associated. Replace all 'struct
mutex' references in the mutex code code with '_mutex_t' which allows to
have a RT specific 'struct mutex' in the final step.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/locking/mutex-debug.c | 12 ++++-----
kernel/locking/mutex.c | 52 +++++++++++++++++++++----------------------
kernel/locking/mutex.h | 14 +++++------
3 files changed, 39 insertions(+), 39 deletions(-)
---
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -25,14 +25,14 @@
/*
* Must be called with lock->wait_lock held.
*/
-void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
+void debug_mutex_lock_common(_mutex_t *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
waiter->magic = waiter;
INIT_LIST_HEAD(&waiter->list);
}

-void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
+void debug_mutex_wake_waiter(_mutex_t *lock, struct mutex_waiter *waiter)
{
lockdep_assert_held(&lock->wait_lock);
DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
@@ -46,7 +46,7 @@ void debug_mutex_free_waiter(struct mute
memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
}

-void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+void debug_mutex_add_waiter(_mutex_t *lock, struct mutex_waiter *waiter,
struct task_struct *task)
{
lockdep_assert_held(&lock->wait_lock);
@@ -55,7 +55,7 @@ void debug_mutex_add_waiter(struct mutex
task->blocked_on = waiter;
}

-void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+void debug_mutex_remove_waiter(_mutex_t *lock, struct mutex_waiter *waiter,
struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
@@ -67,7 +67,7 @@ void debug_mutex_remove_waiter(struct mu
waiter->task = NULL;
}

-void debug_mutex_unlock(struct mutex *lock)
+void debug_mutex_unlock(_mutex_t *lock)
{
if (likely(debug_locks)) {
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
@@ -75,7 +75,7 @@ void debug_mutex_unlock(struct mutex *lo
}
}

-void debug_mutex_init(struct mutex *lock, const char *name,
+void debug_mutex_init(_mutex_t *lock, const char *name,
struct lock_class_key *key)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -66,7 +66,7 @@ EXPORT_SYMBOL(__mutex_t_init);
*
* DO NOT USE (outside of mutex code).
*/
-static inline struct task_struct *__mutex_owner(struct mutex *lock)
+static inline struct task_struct *__mutex_owner(_mutex_t *lock)
{
return (struct task_struct *)(atomic_long_read(&lock->owner) & ~MUTEX_FLAGS);
}
@@ -90,7 +90,7 @@ static inline unsigned long __owner_flag
/*
* Trylock variant that returns the owning task on failure.
*/
-static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock)
+static inline struct task_struct *__mutex_trylock_or_owner(_mutex_t *lock)
{
unsigned long owner, curr = (unsigned long)current;

@@ -133,7 +133,7 @@ static inline struct task_struct *__mute
/*
* Actual trylock that will work on any unlocked state.
*/
-static inline bool __mutex_trylock(struct mutex *lock)
+static inline bool __mutex_trylock(_mutex_t *lock)
{
return !__mutex_trylock_or_owner(lock);
}
@@ -149,7 +149,7 @@ static inline bool __mutex_trylock(struc
* Optimistic trylock that only works in the uncontended case. Make sure to
* follow with a __mutex_trylock() before failing.
*/
-static __always_inline bool __mutex_trylock_fast(struct mutex *lock)
+static __always_inline bool __mutex_trylock_fast(_mutex_t *lock)
{
unsigned long curr = (unsigned long)current;
unsigned long zero = 0UL;
@@ -160,7 +160,7 @@ static __always_inline bool __mutex_tryl
return false;
}

-static __always_inline bool __mutex_unlock_fast(struct mutex *lock)
+static __always_inline bool __mutex_unlock_fast(_mutex_t *lock)
{
unsigned long curr = (unsigned long)current;

@@ -171,17 +171,17 @@ static __always_inline bool __mutex_unlo
}
#endif

-static inline void __mutex_set_flag(struct mutex *lock, unsigned long flag)
+static inline void __mutex_set_flag(_mutex_t *lock, unsigned long flag)
{
atomic_long_or(flag, &lock->owner);
}

-static inline void __mutex_clear_flag(struct mutex *lock, unsigned long flag)
+static inline void __mutex_clear_flag(_mutex_t *lock, unsigned long flag)
{
atomic_long_andnot(flag, &lock->owner);
}

-static inline bool __mutex_waiter_is_first(struct mutex *lock, struct mutex_waiter *waiter)
+static inline bool __mutex_waiter_is_first(_mutex_t *lock, struct mutex_waiter *waiter)
{
return list_first_entry(&lock->wait_list, struct mutex_waiter, list) == waiter;
}
@@ -191,7 +191,7 @@ static inline bool __mutex_waiter_is_fir
* FLAG_WAITERS flag if it's the first waiter.
*/
static void
-__mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+__mutex_add_waiter(_mutex_t *lock, struct mutex_waiter *waiter,
struct list_head *list)
{
debug_mutex_add_waiter(lock, waiter, current);
@@ -202,7 +202,7 @@ static void
}

static void
-__mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter)
+__mutex_remove_waiter(_mutex_t *lock, struct mutex_waiter *waiter)
{
list_del(&waiter->list);
if (likely(list_empty(&lock->wait_list)))
@@ -217,7 +217,7 @@ static void
* WAITERS. Provides RELEASE semantics like a regular unlock, the
* __mutex_trylock() provides a matching ACQUIRE semantics for the handoff.
*/
-static void __mutex_handoff(struct mutex *lock, struct task_struct *task)
+static void __mutex_handoff(_mutex_t *lock, struct task_struct *task)
{
unsigned long owner = atomic_long_read(&lock->owner);

@@ -360,7 +360,7 @@ static inline bool __sched
* __ww_mutex_check_kill() wake any but the earliest context.
*/
static bool __sched
-__ww_mutex_die(struct mutex *lock, struct mutex_waiter *waiter,
+__ww_mutex_die(_mutex_t *lock, struct mutex_waiter *waiter,
struct ww_acquire_ctx *ww_ctx)
{
if (!ww_ctx->is_wait_die)
@@ -382,7 +382,7 @@ static bool __sched
* the lock holders. Even if multiple waiters may wound the lock holder,
* it's sufficient that only one does.
*/
-static bool __ww_mutex_wound(struct mutex *lock,
+static bool __ww_mutex_wound(_mutex_t *lock,
struct ww_acquire_ctx *ww_ctx,
struct ww_acquire_ctx *hold_ctx)
{
@@ -437,7 +437,7 @@ static bool __ww_mutex_wound(struct mute
* The current task must not be on the wait list.
*/
static void __sched
-__ww_mutex_check_waiters(struct mutex *lock, struct ww_acquire_ctx *ww_ctx)
+__ww_mutex_check_waiters(_mutex_t *lock, struct ww_acquire_ctx *ww_ctx)
{
struct mutex_waiter *cur;

@@ -495,7 +495,7 @@ ww_mutex_set_context_fastpath(struct ww_
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER

static inline
-bool ww_mutex_spin_on_owner(struct mutex *lock, struct ww_acquire_ctx *ww_ctx,
+bool ww_mutex_spin_on_owner(_mutex_t *lock, struct ww_acquire_ctx *ww_ctx,
struct mutex_waiter *waiter)
{
struct ww_mutex *ww;
@@ -543,7 +543,7 @@ bool ww_mutex_spin_on_owner(struct mutex
* "noinline" so that this function shows up on perf profiles.
*/
static noinline
-bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner,
+bool mutex_spin_on_owner(_mutex_t *lock, struct task_struct *owner,
struct ww_acquire_ctx *ww_ctx, struct mutex_waiter *waiter)
{
bool ret = true;
@@ -582,7 +582,7 @@ bool mutex_spin_on_owner(struct mutex *l
/*
* Initial check for entering the mutex spinning loop
*/
-static inline int mutex_can_spin_on_owner(struct mutex *lock)
+static inline int mutex_can_spin_on_owner(_mutex_t *lock)
{
struct task_struct *owner;
int retval = 1;
@@ -631,7 +631,7 @@ static inline int mutex_can_spin_on_owne
* changed to itself.
*/
static __always_inline bool
-mutex_optimistic_spin(struct mutex *lock, struct ww_acquire_ctx *ww_ctx,
+mutex_optimistic_spin(_mutex_t *lock, struct ww_acquire_ctx *ww_ctx,
struct mutex_waiter *waiter)
{
if (!waiter) {
@@ -707,14 +707,14 @@ mutex_optimistic_spin(struct mutex *lock
}
#else
static __always_inline bool
-mutex_optimistic_spin(struct mutex *lock, struct ww_acquire_ctx *ww_ctx,
+mutex_optimistic_spin(_mutex_t *lock, struct ww_acquire_ctx *ww_ctx,
struct mutex_waiter *waiter)
{
return false;
}
#endif

-static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigned long ip);
+static noinline void __sched __mutex_unlock_slowpath(_mutex_t *lock, unsigned long ip);

/**
* mutex_unlock - release the mutex
@@ -769,7 +769,7 @@ EXPORT_SYMBOL(ww_mutex_unlock);

static __always_inline int __sched
-__ww_mutex_kill(struct mutex *lock, struct ww_acquire_ctx *ww_ctx)
+__ww_mutex_kill(_mutex_t *lock, struct ww_acquire_ctx *ww_ctx)
{
if (ww_ctx->acquired > 0) {
#ifdef CONFIG_DEBUG_MUTEXES
@@ -798,7 +798,7 @@ static __always_inline int __sched
* look at waiters before us in the wait-list.
*/
static inline int __sched
-__ww_mutex_check_kill(struct mutex *lock, struct mutex_waiter *waiter,
+__ww_mutex_check_kill(_mutex_t *lock, struct mutex_waiter *waiter,
struct ww_acquire_ctx *ctx)
{
struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
@@ -846,7 +846,7 @@ static inline int __sched
*/
static inline int __sched
__ww_mutex_add_waiter(struct mutex_waiter *waiter,
- struct mutex *lock,
+ _mutex_t *lock,
struct ww_acquire_ctx *ww_ctx)
{
struct mutex_waiter *cur;
@@ -919,7 +919,7 @@ static inline int __sched
* Lock a mutex (possibly interruptible), slowpath:
*/
static __always_inline int __sched
-__mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclass,
+__mutex_lock_common(_mutex_t *lock, unsigned int state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
@@ -1101,7 +1101,7 @@ static int __sched
}

static int __sched
-__ww_mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass,
+__ww_mutex_lock(_mutex_t *lock, unsigned int state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
struct ww_acquire_ctx *ww_ctx)
{
@@ -1216,7 +1216,7 @@ EXPORT_SYMBOL_GPL(ww_mutex_lock_interrup
/*
* Release the lock, slowpath:
*/
-static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigned long ip)
+static noinline void __sched __mutex_unlock_slowpath(_mutex_t *lock, unsigned long ip)
{
struct task_struct *next = NULL;
DEFINE_WAKE_Q(wake_q);
--- a/kernel/locking/mutex.h
+++ b/kernel/locking/mutex.h
@@ -21,18 +21,18 @@ struct mutex_waiter {
};

#ifdef CONFIG_DEBUG_MUTEXES
-extern void debug_mutex_lock_common(struct mutex *lock,
+extern void debug_mutex_lock_common(_mutex_t *lock,
struct mutex_waiter *waiter);
-extern void debug_mutex_wake_waiter(struct mutex *lock,
+extern void debug_mutex_wake_waiter(_mutex_t *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
-extern void debug_mutex_add_waiter(struct mutex *lock,
+extern void debug_mutex_add_waiter(_mutex_t *lock,
struct mutex_waiter *waiter,
struct task_struct *task);
-extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+extern void debug_mutex_remove_waiter(_mutex_t *lock, struct mutex_waiter *waiter,
struct task_struct *task);
-extern void debug_mutex_unlock(struct mutex *lock);
-extern void debug_mutex_init(struct mutex *lock, const char *name,
+extern void debug_mutex_unlock(_mutex_t *lock);
+extern void debug_mutex_init(_mutex_t *lock, const char *name,
struct lock_class_key *key);
#else /* CONFIG_DEBUG_MUTEXES */

@@ -44,7 +44,7 @@ extern void debug_mutex_init(struct mute
#define debug_mutex_init(lock, name, key) do { } while (0)

static inline void
-debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
+debug_mutex_lock_common(_mutex_t *lock, struct mutex_waiter *waiter)
{
}
#endif /* !CONFIG_DEBUG_MUTEXES */

Next message: Thomas Gleixner: "[patch 37/50] locking/mutex: Rearrange items in mutex.h"
Previous message: Thomas Gleixner: "[patch 35/50] locking/ww_mutex: Switch to _mutex_t"
In reply to: Thomas Gleixner: "[patch 35/50] locking/ww_mutex: Switch to _mutex_t"
Next in thread: Thomas Gleixner: "[patch 37/50] locking/mutex: Rearrange items in mutex.h"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]