[PATCH 2/8] locking/mutex: Get rid of use_ww_cxt param in common paths

From: Davidlohr Bueso
Date: Sun Dec 28 2014 - 04:14:34 EST

... and simplify a bit the parameters of __mutex_lock_common(). This
is straightforward as we can just check if the ww cxt for NULL if passed
from non wait/wound paths.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
kernel/locking/mutex.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 4541951..2e687a8 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -300,7 +300,7 @@ static inline bool mutex_try_to_acquire(struct mutex *lock)
* that we need to jump to the slowpath and sleep.
*/
static bool mutex_optimistic_spin(struct mutex *lock,
- struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
+ struct ww_acquire_ctx *ww_ctx)
{
struct task_struct *task = current;

@@ -313,7 +313,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
while (true) {
struct task_struct *owner;

- if (use_ww_ctx && ww_ctx->acquired > 0) {
+ if (ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;

ww = container_of(lock, struct ww_mutex, base);
@@ -341,7 +341,7 @@ static bool mutex_optimistic_spin(struct mutex *lock,
if (mutex_try_to_acquire(lock)) {
lock_acquired(&lock->dep_map, ip);

- if (use_ww_ctx) {
+ if (ww_ctx) {
struct ww_mutex *ww;
ww = container_of(lock, struct ww_mutex, base);

@@ -391,7 +391,7 @@ done:
}
#else
static bool mutex_optimistic_spin(struct mutex *lock,
- struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
+ struct ww_acquire_ctx *ww_ctx)
{
return false;
}
@@ -498,7 +498,7 @@ __mutex_lock_check_stamp(struct mutex *lock, struct ww_acquire_ctx *ctx)
static __always_inline int __sched
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
- struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
+ struct ww_acquire_ctx *ww_ctx)
{
struct task_struct *task = current;
struct mutex_waiter waiter;
@@ -508,7 +508,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
preempt_disable();
mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);

- if (mutex_optimistic_spin(lock, ww_ctx, use_ww_ctx)) {
+ if (mutex_optimistic_spin(lock, ww_ctx)) {
/* got the lock, yay! */
preempt_enable();
return 0;
@@ -556,7 +556,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
goto err;
}

- if (use_ww_ctx && ww_ctx->acquired > 0) {
+ if (ww_ctx && ww_ctx->acquired > 0) {
ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
goto err;
@@ -580,7 +580,7 @@ skip_wait:
lock_acquired(&lock->dep_map, ip);
mutex_set_owner(lock);

- if (use_ww_ctx) {
+ if (ww_ctx) {
struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
struct mutex_waiter *cur;

@@ -620,7 +620,7 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL, 0);
+ subclass, NULL, _RET_IP_, NULL);
}

EXPORT_SYMBOL_GPL(mutex_lock_nested);
@@ -630,7 +630,7 @@ _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
{
might_sleep();
__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
- 0, nest, _RET_IP_, NULL, 0);
+ 0, nest, _RET_IP_, NULL);
}

EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock);
@@ -640,7 +640,7 @@ mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_KILLABLE,
- subclass, NULL, _RET_IP_, NULL, 0);
+ subclass, NULL, _RET_IP_, NULL);
}
EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);

@@ -649,7 +649,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
might_sleep();
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
- subclass, NULL, _RET_IP_, NULL, 0);
+ subclass, NULL, _RET_IP_, NULL);
}

EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -687,7 +687,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)

might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx, 1);
+ 0, &ctx->dep_map, _RET_IP_, ctx);
if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);

@@ -702,7 +702,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)

might_sleep();
ret = __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE,
- 0, &ctx->dep_map, _RET_IP_, ctx, 1);
+ 0, &ctx->dep_map, _RET_IP_, ctx);

if (!ret && ctx->acquired > 1)
return ww_mutex_deadlock_injection(lock, ctx);
@@ -822,28 +822,28 @@ __mutex_lock_slowpath(atomic_t *lock_count)
struct mutex *lock = container_of(lock_count, struct mutex, count);

__mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL, 0);
+ NULL, _RET_IP_, NULL);
}

static noinline int __sched
__mutex_lock_killable_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_KILLABLE, 0,
- NULL, _RET_IP_, NULL, 0);
+ NULL, _RET_IP_, NULL);
}

static noinline int __sched
__mutex_lock_interruptible_slowpath(struct mutex *lock)
{
return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, NULL, 0);
+ NULL, _RET_IP_, NULL);
}

static noinline int __sched
__ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_UNINTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx, 1);
+ NULL, _RET_IP_, ctx);
}

static noinline int __sched
@@ -851,7 +851,7 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock,
struct ww_acquire_ctx *ctx)
{
return __mutex_lock_common(&lock->base, TASK_INTERRUPTIBLE, 0,
- NULL, _RET_IP_, ctx, 1);
+ NULL, _RET_IP_, ctx);
}

#endif
--
2.1.2

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