sched/preempt: Use CONFIG_PREEMPTION where appropriate

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.

Switch the preemption code, scheduler and init task over to use
CONFIG_PREEMPTION.

That's the first step towards RT in that area. The more complex changes are
coming separately.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.117528401@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/init/init_task.c b/init/init_task.c
index 7ab773b9b3cd..bfe06c53b14e 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -174,7 +174,7 @@ struct task_struct init_task
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         .ret_stack      = NULL,
 #endif
-#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
         .trace_recursion = 0,
 #endif
 #ifdef CONFIG_LIVEPATCH
diff --git a/init/main.c b/init/main.c
index 96f8d5af52d6..653693da8da6 100644
--- a/init/main.c
+++ b/init/main.c
@@ -433,7 +433,7 @@ noinline void __ref rest_init(void)
 
         /*
          * Enable might_sleep() and smp_processor_id() checks.
-         * They cannot be enabled earlier because with CONFIG_PREEMPT=y
+         * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
          * kernel_thread() would trigger might_sleep() splats. With
          * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
          * already, but it's stuck on the kthreadd_done completion.