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Subject[tip:sched/core] sched/core: Simplify INIT_PREEMPT_COUNT
Commit-ID:  aed586c2f11e5cddd52c180ccde651d0d35b736b
Gitweb: http://git.kernel.org/tip/aed586c2f11e5cddd52c180ccde651d0d35b736b
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Tue, 29 Sep 2015 11:28:26 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 29 Sep 2015 12:27:39 +0200

sched/core: Simplify INIT_PREEMPT_COUNT

As per commit d86ee4809d03 ("sched: optimize cond_resched()") we
need PREEMPT_ACTIVE to avoid cond_resched() from working before
the scheduler is setup.

However, keeping preemption disabled should do the same thing
already, making the PREEMPT_ACTIVE part entirely redundant.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: rostedt@goodmis.org
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150929093519.706413197@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched.h | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 699228b..5ef9e2c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -608,17 +608,14 @@ struct task_cputime_atomic {
/*
* Disable preemption until the scheduler is running.
* Reset by start_kernel()->sched_init()->init_idle().
- *
- * We include PREEMPT_ACTIVE to avoid cond_resched() from working
- * before the scheduler is active -- see should_resched().
*/
-#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
+#define INIT_PREEMPT_COUNT PREEMPT_DISABLED

/**
* struct thread_group_cputimer - thread group interval timer counts
* @cputime_atomic: atomic thread group interval timers.
* @running: non-zero when there are timers running and
- * @cputime receives updates.
+ * @cputime receives updates.
*
* This structure contains the version of task_cputime, above, that is
* used for thread group CPU timer calculations.

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