Prev: [PATCH 10/12] rwsem: down_read_unfair infrastructure support
Next: [PATCH 04/12] rwsem: consistently use adjustment variable
From: Michel Lespinasse on 11 May 2010 23:30
More code can be pushed from rwsem_down_read_failed and
rwsem_down_write_failed into rwsem_down_failed_common.

Following change also enjoys having flags available in a register rather
than having to fish it out in the struct rwsem_waiter...

Signed-off-by: Michel Lespinasse <walken(a)google.com>
---
lib/rwsem.c | 23 +++++++++--------------
1 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/lib/rwsem.c b/lib/rwsem.c
index 84bbc55..1702524 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -158,8 +158,9 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wake_type)
*/
static struct rw_semaphore __sched *
rwsem_down_failed_common(struct rw_semaphore *sem,
- struct rwsem_waiter *waiter, signed long adjustment)
+ unsigned int flags, signed long adjustment)
{
+ struct rwsem_waiter waiter;
struct task_struct *tsk = current;
signed long count;

@@ -167,7 +168,8 @@ rwsem_down_failed_common(struct rw_semaphore *sem,

/* set up my own style of waitqueue */
spin_lock_irq(&sem->wait_lock);
- waiter->task = tsk;
+ waiter.task = tsk;
+ waiter.flags = flags;
get_task_struct(tsk);

if (list_empty(&sem->wait_list))
@@ -192,7 +194,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,

/* wait to be given the lock */
for (;;) {
- if (!waiter->task)
+ if (!waiter.task)
break;
schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
@@ -209,11 +211,8 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
asmregparm struct rw_semaphore __sched *
rwsem_down_read_failed(struct rw_semaphore *sem)
{
- struct rwsem_waiter waiter;
-
- waiter.flags = RWSEM_WAITING_FOR_READ;
- rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_READ_BIAS);
- return sem;
+ return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_READ,
+ -RWSEM_ACTIVE_READ_BIAS);
}

/*
@@ -222,12 +221,8 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
asmregparm struct rw_semaphore __sched *
rwsem_down_write_failed(struct rw_semaphore *sem)
{
- struct rwsem_waiter waiter;
-
- waiter.flags = RWSEM_WAITING_FOR_WRITE;
- rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_WRITE_BIAS);
-
- return sem;
+ return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_WRITE,
+ -RWSEM_ACTIVE_WRITE_BIAS);
}

/*
--
1.7.0.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: [PATCH 10/12] rwsem: down_read_unfair infrastructure support
Next: [PATCH 04/12] rwsem: consistently use adjustment variable