Re: [PATCH 2/4] futex,plist: remove debug lock assignment for plist_node

[Darren Hart <dvhart@linux.intel.com>]

On 12/21/2010 01:55 AM, Lai Jiangshan wrote:
> original code use&plist_node->plist as the faked head of
> the priority list for plist_del(), these debug locks in
> the faked head are needed for CONFIG_DEBUG_PI_LIST.
>
> But now we always pass the real head to plist_del(), the debug locks
> in plist_node will not be used, so we remove these assignments.
>
> Signed-off-by:  Lai Jiangshan<laijs@cn.fujitsu.com>

Acked-by: Darren Hart <dvhart@linux.intel.com>

> ---
> diff --git a/kernel/futex.c b/kernel/futex.c
> index 6c4f67a..725834e 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -1032,9 +1032,6 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
>   		plist_del(&q->list,&hb1->chain);
>   		plist_add(&q->list,&hb2->chain);
>   		q->lock_ptr =&hb2->lock;
> -#ifdef CONFIG_DEBUG_PI_LIST
> -		q->list.plist.spinlock =&hb2->lock;
> -#endif
>   	}
>   	get_futex_key_refs(key2);
>   	q->key = *key2;
> @@ -1068,9 +1065,6 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
>   	q->rt_waiter = NULL;
>
>   	q->lock_ptr =&hb->lock;
> -#ifdef CONFIG_DEBUG_PI_LIST
> -	q->list.plist.spinlock =&hb->lock;
> -#endif
>
>   	wake_up_state(q->task, TASK_NORMAL);
>   }
> @@ -1418,9 +1412,6 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
>   	prio = min(current->normal_prio, MAX_RT_PRIO);
>
>   	plist_node_init(&q->list, prio);
> -#ifdef CONFIG_DEBUG_PI_LIST
> -	q->list.plist.spinlock =&hb->lock;
> -#endif
>   	plist_add(&q->list,&hb->chain);
>   	q->task = current;
>   	spin_unlock(&hb->lock);


-- 
Darren Hart
Yocto Linux Kernel