2009-03-02 05:55:48

by Wang Chen

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

based on tip/sched/cleanups

impact: no change in functionality

Parameter "prev" seems like an unusable thing.

Signed-off-by: Wang Chen <[email protected]>
---
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);
- next = pick_next_task(rq, prev);
+ next = pick_next_task(rq);

if (likely(prev != next)) {
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);
--
1.5.3.4

2009-03-02 06:13:50

by Cong Wang

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

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 <[email protected]>
>---
> 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? :)

>- 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'.


--
Do what you love, f**k the rest! F**k the regulations!

2009-03-02 06:53:24

by Wang Chen

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

Am?rico 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 <[email protected]>
>> ---
>> 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'.
>

2009-03-02 07:44:27

by Cong Wang

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

On Mon, Mar 02, 2009 at 02:52:54PM +0800, Wang Chen wrote:
>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 <[email protected]>
>>> ---
>>> 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)".
>;)
>

Oops, I misread the patch. Then it's OK. :)


--
Do what you love, f**k the rest! F**k the regulations!