[tip: core/rcu] sched: Cleanup PREEMPT_COUNT leftovers

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     4a291f57d97ce1c14d286b2451573ccbb3b43022
Gitweb:        https://git.kernel.org/tip/4a291f57d97ce1c14d286b2451573ccbb3b43022
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Mon, 14 Sep 2020 19:30:49 +02:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 28 Sep 2020 16:03:21 -07:00

sched: Cleanup PREEMPT_COUNT leftovers

CONFIG_PREEMPT_COUNT is now unconditionally enabled and will be
removed. Cleanup the leftovers before doing so.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/sched/core.c | 6 +-----
 lib/Kconfig.debug   | 1 -
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2d95dc3..1c304a1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3706,8 +3706,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev)
 	 * finish_task_switch() for details.
 	 *
 	 * finish_task_switch() will drop rq->lock() and lower preempt_count
-	 * and the preempt_enable() will end up enabling preemption (on
-	 * PREEMPT_COUNT kernels).
+	 * and the preempt_enable() will end up enabling preemption.
 	 */
 
 	rq = finish_task_switch(prev);
@@ -7308,9 +7307,6 @@ void __cant_sleep(const char *file, int line, int preempt_offset)
 	if (irqs_disabled())
 		return;
 
-	if (!IS_ENABLED(CONFIG_PREEMPT_COUNT))
-		return;
-
 	if (preempt_count() > preempt_offset)
 		return;
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d4d0574..52af6ad 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1320,7 +1320,6 @@ config DEBUG_LOCKDEP
 
 config DEBUG_ATOMIC_SLEEP
 	bool "Sleep inside atomic section checking"
-	select PREEMPT_COUNT
 	depends on DEBUG_KERNEL
 	help
 	  If you say Y here, various routines which may sleep will become very