context_tracking: Wrap static key check into more intuitive function …

…name

Use a function with a meaningful name to check the global context
tracking state. static_key_false() is a bit confusing for reviewers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

include/linux/context_tracking.h

@@ -17,21 +17,21 @@ extern void __context_tracking_task_switch(struct task_struct *prev,
 
 static inline void user_enter(void)
 {
-	if (static_key_false(&context_tracking_enabled))
+	if (context_tracking_is_enabled())
 		context_tracking_user_enter();
 
 }
 static inline void user_exit(void)
 {
-	if (static_key_false(&context_tracking_enabled))
+	if (context_tracking_is_enabled())
 		context_tracking_user_exit();
 }
 
 static inline enum ctx_state exception_enter(void)
 {
 	enum ctx_state prev_ctx;
 
-	if (!static_key_false(&context_tracking_enabled))
+	if (!context_tracking_is_enabled())
 		return 0;
 
 	prev_ctx = this_cpu_read(context_tracking.state);
@@ -42,7 +42,7 @@ static inline enum ctx_state exception_enter(void)
 
 static inline void exception_exit(enum ctx_state prev_ctx)
 {
-	if (static_key_false(&context_tracking_enabled)) {
+	if (context_tracking_is_enabled()) {
 		if (prev_ctx == IN_USER)
 			context_tracking_user_enter();
 	}
@@ -51,7 +51,7 @@ static inline void exception_exit(enum ctx_state prev_ctx)
 static inline void context_tracking_task_switch(struct task_struct *prev,
 						struct task_struct *next)
 {
-	if (static_key_false(&context_tracking_enabled))
+	if (context_tracking_is_enabled())
 		__context_tracking_task_switch(prev, next);
 }
 #else

include/linux/context_tracking_state.h

@@ -22,6 +22,10 @@ struct context_tracking {
 extern struct static_key context_tracking_enabled;
 DECLARE_PER_CPU(struct context_tracking, context_tracking);
 
+static inline bool context_tracking_is_enabled(void)
+{
+	return static_key_false(&context_tracking_enabled);
+}
 static inline bool context_tracking_in_user(void)
 {
 	return __this_cpu_read(context_tracking.state) == IN_USER;

include/linux/tick.h

@@ -165,7 +165,7 @@ extern cpumask_var_t tick_nohz_full_mask;
 
 static inline bool tick_nohz_full_enabled(void)
 {
-	if (!static_key_false(&context_tracking_enabled))
+	if (!context_tracking_is_enabled())
 		return false;
 
 	return tick_nohz_full_running;

include/linux/vtime.h

@@ -19,7 +19,7 @@ static inline bool vtime_accounting_enabled(void) { return true; }
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 static inline bool vtime_accounting_enabled(void)
 {
-	if (static_key_false(&context_tracking_enabled)) {
+	if (context_tracking_is_enabled()) {
 		if (context_tracking_active())
 			return true;
 	}

kernel/context_tracking.c

@@ -53,10 +53,10 @@ void context_tracking_user_enter(void)
 	/*
 	 * Repeat the user_enter() check here because some archs may be calling
 	 * this from asm and if no CPU needs context tracking, they shouldn't
-	 * go further. Repeat the check here until they support the static key
-	 * check.
+	 * go further. Repeat the check here until they support the inline static
+	 * key check.
 	 */
-	if (!static_key_false(&context_tracking_enabled))
+	if (!context_tracking_is_enabled())
 		return;
 
 	/*
@@ -160,7 +160,7 @@ void context_tracking_user_exit(void)
 {
 	unsigned long flags;
 
-	if (!static_key_false(&context_tracking_enabled))
+	if (!context_tracking_is_enabled())
 		return;
 
 	if (in_interrupt())