[tip:x86/asm] context_tracking: Switch to new static_branch API

tip-bot for Andy Lutomirski
2015-11-24T09:39:49Z

Commit-ID: ed11a7f1b3bd482bd7d6ef7bc2859c41fb43b9ee
Gitweb: http://git.kernel.org/tip/ed11a7f1b3bd482bd7d6ef7bc2859c41fb43b9ee
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 12 Nov 2015 12:59:01 -0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 24 Nov 2015 09:56:43 +0100

context_tracking: Switch to new static_branch API

This is much less error-prone than the old code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/812df7e64f120c5c7c08481f36a8caa9f53b2199.1447361906.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/context_tracking_state.h | 4 ++--
kernel/context_tracking.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
index ee956c5..1d34fe6 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -22,12 +22,12 @@ struct context_tracking {
};

#ifdef CONFIG_CONTEXT_TRACKING
-extern struct static_key context_tracking_enabled;
+extern struct static_key_false 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);
+ return static_branch_unlikely(&context_tracking_enabled);
}

static inline bool context_tracking_cpu_is_enabled(void)
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index d8560ee..9ad37b9 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -24,7 +24,7 @@
#define CREATE_TRACE_POINTS
#include <trace/events/context_tracking.h>

-struct static_key context_tracking_enabled = STATIC_KEY_INIT_FALSE;
+DEFINE_STATIC_KEY_FALSE(context_tracking_enabled);
EXPORT_SYMBOL_GPL(context_tracking_enabled);

DEFINE_PER_CPU(struct context_tracking, context_tracking);
@@ -191,7 +191,7 @@ void __init context_tracking_cpu_set(int cpu)

if (!per_cpu(context_tracking.active, cpu)) {
per_cpu(context_tracking.active, cpu) = true;
- static_key_slow_inc(&context_tracking_enabled);
+ static_branch_inc(&context_tracking_enabled);
}

if (initialized)