[PATCH 3/6] context_tracking: Wrap static key check into more intuitive function name

From: Frederic Weisbecker
Date: Thu Nov 07 2013 - 13:17:27 EST


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@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/linux/context_tracking.h | 10 +++++-----
include/linux/context_tracking_state.h | 4 ++++
include/linux/tick.h | 2 +-
include/linux/vtime.h | 2 +-
kernel/context_tracking.c | 8 ++++----
5 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 1581587..37b81bd 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -17,13 +17,13 @@ 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();
}

@@ -31,7 +31,7 @@ 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
diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
index 0f1979d..0db535b 100644
--- a/include/linux/context_tracking_state.h
+++ b/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;
diff --git a/include/linux/tick.h b/include/linux/tick.h
index a004f66..0175d86 100644
--- a/include/linux/tick.h
+++ b/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;
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index f5b72b3..807c732 100644
--- a/include/linux/vtime.h
+++ b/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;
}
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 859c8df..1104817 100644
--- a/kernel/context_tracking.c
+++ b/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())
--
1.8.3.1

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