Re: [PATCH] sched: kill unused parameter of pick_next_task()

[Wang Chen <wangchen@cn.fujitsu.com>]

Américo Wang said the following on 2009-3-2 14:13:
> On Mon, Mar 02, 2009 at 01:55:26PM +0800, Wang Chen wrote:
>> based on tip/sched/cleanups
>>
>> impact: no change in functionality
>>
>> Parameter "prev" seems like an unusable thing.
>>
>> Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
>> ---
>> kernel/sched.c |    6 +++---
>> 1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/sched.c b/kernel/sched.c
>> index 410eec4..57f8b12 100644
>> --- a/kernel/sched.c
>> +++ b/kernel/sched.c
>> @@ -4512,7 +4512,7 @@ static inline void schedule_debug(struct task_struct *prev)
>>  * Pick up the highest-prio task:
>>  */
>> static inline struct task_struct *
>> -pick_next_task(struct rq *rq, struct task_struct *prev)
>> +pick_next_task(struct rq *rq)
>> {
>> 	const struct sched_class *class;
>> 	struct task_struct *p;
>> @@ -4587,7 +4587,7 @@ need_resched_nonpreemptible:
>> 		idle_balance(cpu, rq);
>>
>> 	prev->sched_class->put_prev_task(rq, prev);
>         ^^^^^
> 
> How about this? :)
> 

need_resched_nonpreemptible is inside another function instead of pick_next_task().
Because "diff" doesn't know "asmlinkage void __sched schedule(void)".
;)

>> -	next = pick_next_task(rq, prev);
>> +	next = pick_next_task(rq);
>>
>> 	if (likely(prev != next)) {
>                    ^^^^
> 
> also here.
> 
>> 		sched_info_switch(prev, next);
>> @@ -6423,7 +6423,7 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
>> 		if (!rq->nr_running)
>> 			break;
>> 		update_rq_clock(rq);
>> -		next = pick_next_task(rq, rq->curr);
>> +		next = pick_next_task(rq);
>> 		if (!next)
>> 			break;
>> 		next->sched_class->put_prev_task(rq, next);
> 
> 
> I think you should check the latest linus-git, where you can safely
> just remove the parameter 'prev'.
>