[PATCH 1/3] context_tracking: remove duplicate enabled check

From: Paolo Bonzini
Date: Tue Oct 27 2015 - 21:40:42 EST


All calls to context_tracking_enter and context_tracking_exit
are already checking context_tracking_is_enabled, except the
context_tracking_user_enter and context_tracking_user_exit
functions left in for the benefit of assembly calls.

Pull the check up to those functions, by making them simple
wrappers around the user_enter and user_exit inline functions.

Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
include/linux/context_tracking.h | 4 ++--
kernel/context_tracking.c | 16 ++--------------
2 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 008fc67d0d96..6ef136ff0897 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -18,13 +18,13 @@ extern void context_tracking_user_exit(void);
static inline void user_enter(void)
{
if (context_tracking_is_enabled())
- context_tracking_user_enter();
+ context_tracking_enter(CONTEXT_USER);

}
static inline void user_exit(void)
{
if (context_tracking_is_enabled())
- context_tracking_user_exit();
+ context_tracking_exit(CONTEXT_USER);
}

static inline enum ctx_state exception_enter(void)
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 0a495ab35bc7..6d4c6ce21275 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -63,15 +63,6 @@ void context_tracking_enter(enum ctx_state state)
unsigned long flags;

/*
- * 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 inline static
- * key check.
- */
- if (!context_tracking_is_enabled())
- return;
-
- /*
* Some contexts may involve an exception occuring in an irq,
* leading to that nesting:
* rcu_irq_enter() rcu_user_exit() rcu_user_exit() rcu_irq_exit()
@@ -128,7 +119,7 @@ EXPORT_SYMBOL_GPL(context_tracking_enter);

void context_tracking_user_enter(void)
{
- context_tracking_enter(CONTEXT_USER);
+ user_enter();
}
NOKPROBE_SYMBOL(context_tracking_user_enter);

@@ -148,9 +139,6 @@ void context_tracking_exit(enum ctx_state state)
{
unsigned long flags;

- if (!context_tracking_is_enabled())
- return;
-
if (in_interrupt())
return;

@@ -181,7 +169,7 @@ EXPORT_SYMBOL_GPL(context_tracking_exit);

void context_tracking_user_exit(void)
{
- context_tracking_exit(CONTEXT_USER);
+ user_exit();
}
NOKPROBE_SYMBOL(context_tracking_user_exit);

--
2.5.0


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