context_tracking: Optimize context switch off case with static keys

No need for syscall slowpath if no CPU is full dynticks,
rather nop this in this case.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
This commit is contained in:
Frederic Weisbecker
2013-07-11 19:42:13 +02:00
parent 48d6a816a8
commit 73d424f9af
2 changed files with 12 additions and 5 deletions

View File

@@ -166,7 +166,7 @@ void context_tracking_user_exit(void)
}
/**
* context_tracking_task_switch - context switch the syscall callbacks
* __context_tracking_task_switch - context switch the syscall callbacks
* @prev: the task that is being switched out
* @next: the task that is being switched in
*
@@ -178,8 +178,8 @@ void context_tracking_user_exit(void)
* migrate to some CPU that doesn't do the context tracking. As such the TIF
* flag may not be desired there.
*/
void context_tracking_task_switch(struct task_struct *prev,
struct task_struct *next)
void __context_tracking_task_switch(struct task_struct *prev,
struct task_struct *next)
{
clear_tsk_thread_flag(prev, TIF_NOHZ);
set_tsk_thread_flag(next, TIF_NOHZ);