* [PATCH] sched/core: Remove unnecessary initialization init_idle_bootup_task()
@ 2017-08-04 9:19 Cheng Jian
2017-08-04 9:43 ` Peter Zijlstra
2017-08-10 12:09 ` [tip:sched/core] " tip-bot for Cheng Jian
0 siblings, 2 replies; 3+ messages in thread
From: Cheng Jian @ 2017-08-04 9:19 UTC (permalink / raw)
To: mingo, peterz, akpm; +Cc: linux-kernel, xiexiuqi, huawei.libin, cj.chengjian
init_idle_bootup_task( ) is called in rest_init( ) to switch
the scheduling class of the boot thread to the idle class
the function only set :
idle->sched_class = &idle_sched_class;
which has been set in init_idle() called by sched_init()
/*
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
We've already set the boot thread to idle class in
start_kernel()->sched_init()->init_idle()
so it's unnecessary to set it again in
start_kernel()->rest_init()->init_idle_bootup_task()
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
---
include/linux/sched/task.h | 1 -
init/main.c | 1 -
kernel/sched/core.c | 5 -----
3 files changed, 7 deletions(-)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index c97e5f0..79a2a74 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -30,7 +30,6 @@
extern asmlinkage void schedule_tail(struct task_struct *prev);
extern void init_idle(struct task_struct *idle, int cpu);
-extern void init_idle_bootup_task(struct task_struct *idle);
extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
extern void sched_dead(struct task_struct *p);
diff --git a/init/main.c b/init/main.c
index 052481f..881d624 100644
--- a/init/main.c
+++ b/init/main.c
@@ -430,7 +430,6 @@ static noinline void __ref rest_init(void)
* The boot idle thread must execute schedule()
* at least once to get things moving:
*/
- init_idle_bootup_task(current);
schedule_preempt_disabled();
/* Call into cpu_idle with preempt disabled */
cpu_startup_entry(CPUHP_ONLINE);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0869b20..7377cac 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5177,11 +5177,6 @@ void show_state_filter(unsigned long state_filter)
debug_show_all_locks();
}
-void init_idle_bootup_task(struct task_struct *idle)
-{
- idle->sched_class = &idle_sched_class;
-}
-
/**
* init_idle - set up an idle thread for a given CPU
* @idle: task in question
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] sched/core: Remove unnecessary initialization init_idle_bootup_task()
2017-08-04 9:19 [PATCH] sched/core: Remove unnecessary initialization init_idle_bootup_task() Cheng Jian
@ 2017-08-04 9:43 ` Peter Zijlstra
2017-08-10 12:09 ` [tip:sched/core] " tip-bot for Cheng Jian
1 sibling, 0 replies; 3+ messages in thread
From: Peter Zijlstra @ 2017-08-04 9:43 UTC (permalink / raw)
To: Cheng Jian; +Cc: mingo, akpm, linux-kernel, xiexiuqi, huawei.libin
On Fri, Aug 04, 2017 at 05:19:37PM +0800, Cheng Jian wrote:
> init_idle_bootup_task( ) is called in rest_init( ) to switch
> the scheduling class of the boot thread to the idle class
>
> the function only set :
> idle->sched_class = &idle_sched_class;
> which has been set in init_idle() called by sched_init()
> /*
> * The idle tasks have their own, simple scheduling class:
> */
> idle->sched_class = &idle_sched_class;
>
> We've already set the boot thread to idle class in
> start_kernel()->sched_init()->init_idle()
> so it's unnecessary to set it again in
> start_kernel()->rest_init()->init_idle_bootup_task()
Yeah, does look a bit redundant. Thanks!
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:sched/core] sched/core: Remove unnecessary initialization init_idle_bootup_task()
2017-08-04 9:19 [PATCH] sched/core: Remove unnecessary initialization init_idle_bootup_task() Cheng Jian
2017-08-04 9:43 ` Peter Zijlstra
@ 2017-08-10 12:09 ` tip-bot for Cheng Jian
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Cheng Jian @ 2017-08-10 12:09 UTC (permalink / raw)
To: linux-tip-commits
Cc: akpm, mingo, hpa, xiexiuqi, torvalds, cj.chengjian, huawei.libin,
tglx, peterz, linux-kernel
Commit-ID: 18f08dae19990f5fffde92e3a63e0d90cda0f1a8
Gitweb: http://git.kernel.org/tip/18f08dae19990f5fffde92e3a63e0d90cda0f1a8
Author: Cheng Jian <cj.chengjian@huawei.com>
AuthorDate: Fri, 4 Aug 2017 17:19:37 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 10 Aug 2017 12:18:18 +0200
sched/core: Remove unnecessary initialization init_idle_bootup_task()
init_idle_bootup_task( ) is called in rest_init( ) to switch
the scheduling class of the boot thread to the idle class.
the function only sets:
idle->sched_class = &idle_sched_class;
which has been set in init_idle() called by sched_init():
/*
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
We've already set the boot thread to idle class in
start_kernel()->sched_init()->init_idle()
so it's unnecessary to set it again in
start_kernel()->rest_init()->init_idle_bootup_task()
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <huawei.libin@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1501838377-109720-1-git-send-email-cj.chengjian@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched/task.h | 1 -
init/main.c | 1 -
kernel/sched/core.c | 5 -----
3 files changed, 7 deletions(-)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index c97e5f0..79a2a74 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -30,7 +30,6 @@ extern int lockdep_tasklist_lock_is_held(void);
extern asmlinkage void schedule_tail(struct task_struct *prev);
extern void init_idle(struct task_struct *idle, int cpu);
-extern void init_idle_bootup_task(struct task_struct *idle);
extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
extern void sched_dead(struct task_struct *p);
diff --git a/init/main.c b/init/main.c
index 052481f..881d624 100644
--- a/init/main.c
+++ b/init/main.c
@@ -430,7 +430,6 @@ static noinline void __ref rest_init(void)
* The boot idle thread must execute schedule()
* at least once to get things moving:
*/
- init_idle_bootup_task(current);
schedule_preempt_disabled();
/* Call into cpu_idle with preempt disabled */
cpu_startup_entry(CPUHP_ONLINE);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 835a234..6d91c10 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5177,11 +5177,6 @@ void show_state_filter(unsigned long state_filter)
debug_show_all_locks();
}
-void init_idle_bootup_task(struct task_struct *idle)
-{
- idle->sched_class = &idle_sched_class;
-}
-
/**
* init_idle - set up an idle thread for a given CPU
* @idle: task in question
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2017-08-04 9:19 [PATCH] sched/core: Remove unnecessary initialization init_idle_bootup_task() Cheng Jian
2017-08-04 9:43 ` Peter Zijlstra
2017-08-10 12:09 ` [tip:sched/core] " tip-bot for Cheng Jian
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