[PATCH] sched: Drop try_get_task_struct()

[PATCH] sched: Drop try_get_task_struct()

[Davidlohr Bueso]

This function was introduced by 150593b (sched/api: Introduce
task_rcu_dereference() and try_get_task_struct()), to allow
easier usage of task_rcu_dereference(), however no users
were ever added. Drop the helper.

Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 include/linux/sched/task.h |  2 --
 kernel/exit.c              | 13 -------------
 2 files changed, 15 deletions(-)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index a978d7189cfd..f0f065c5afcf 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -95,8 +95,6 @@ static inline void put_task_struct(struct task_struct *t)
 }
 
 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
-struct task_struct *try_get_task_struct(struct task_struct **ptask);
-
 
 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
 extern int arch_task_struct_size __read_mostly;
diff --git a/kernel/exit.c b/kernel/exit.c
index d0a34e1e4ec1..0479eb8b4985 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -317,19 +317,6 @@ void rcuwait_wake_up(struct rcuwait *w)
 	rcu_read_unlock();
 }
 
-struct task_struct *try_get_task_struct(struct task_struct **ptask)
-{
-	struct task_struct *task;
-
-	rcu_read_lock();
-	task = task_rcu_dereference(ptask);
-	if (task)
-		get_task_struct(task);
-	rcu_read_unlock();
-
-	return task;
-}
-
 /*
  * Determine if a process group is "orphaned", according to the POSIX
  * definition in 2.2.2.52.  Orphaned process groups are not to be affected
-- 
2.12.0

[tip:sched/core] sched/core: Drop the unused try_get_task_struct() helper function

[tip-bot for Davidlohr Bueso]

Commit-ID:  f11cc0760b8397e0d230122606421b6a96e9f869
Gitweb:     http://git.kernel.org/tip/f11cc0760b8397e0d230122606421b6a96e9f869
Author:     Davidlohr Bueso <dave@stgolabs.net>
AuthorDate: Wed, 14 Jun 2017 19:37:30 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 20 Jun 2017 12:48:37 +0200

sched/core: Drop the unused try_get_task_struct() helper function

This function was introduced by:

  150593bf8693 ("sched/api: Introduce task_rcu_dereference() and try_get_task_struct()")

... to allow easier usage of task_rcu_dereference(), however no users
were ever added. Drop the helper.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/20170615023730.22827-1-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/sched/task.h |  2 --
 kernel/exit.c              | 13 -------------
 2 files changed, 15 deletions(-)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index a978d71..f0f065c 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -95,8 +95,6 @@ static inline void put_task_struct(struct task_struct *t)
 }
 
 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
-struct task_struct *try_get_task_struct(struct task_struct **ptask);
-
 
 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
 extern int arch_task_struct_size __read_mostly;
diff --git a/kernel/exit.c b/kernel/exit.c
index 7d69443..c632262 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -318,19 +318,6 @@ void rcuwait_wake_up(struct rcuwait *w)
 	rcu_read_unlock();
 }
 
-struct task_struct *try_get_task_struct(struct task_struct **ptask)
-{
-	struct task_struct *task;
-
-	rcu_read_lock();
-	task = task_rcu_dereference(ptask);
-	if (task)
-		get_task_struct(task);
-	rcu_read_unlock();
-
-	return task;
-}
-
 /*
  * Determine if a process group is "orphaned", according to the POSIX
  * definition in 2.2.2.52.  Orphaned process groups are not to be affected