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authorIngo Molnar <mingo@kernel.org>2013-09-28 08:50:09 +0200
committerIngo Molnar <mingo@kernel.org>2013-09-28 08:50:09 +0200
commit62d08aec6a9f4b45cc9cba1e3b2855995df133e6 (patch)
tree51bddd857fb0eb03cd16c9ae17369e81b8f970f4
parent82dfaa58a79c121be3611ce549dec806f2e6004f (diff)
parent0c06a5d4b13cd66c833805a0d1db76b977944aac (diff)
downloadlinaro-lsk-62d08aec6a9f4b45cc9cba1e3b2855995df133e6.tar.gz
Merge branch 'context_tracking/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/urgent
Pull context tracking ARM fix from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/arm/kernel/entry-header.S8
-rw-r--r--kernel/context_tracking.c12
2 files changed, 16 insertions, 4 deletions
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index de23a9beed1..39f89fbd511 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -329,10 +329,10 @@
#ifdef CONFIG_CONTEXT_TRACKING
.if \save
stmdb sp!, {r0-r3, ip, lr}
- bl user_exit
+ bl context_tracking_user_exit
ldmia sp!, {r0-r3, ip, lr}
.else
- bl user_exit
+ bl context_tracking_user_exit
.endif
#endif
.endm
@@ -341,10 +341,10 @@
#ifdef CONFIG_CONTEXT_TRACKING
.if \save
stmdb sp!, {r0-r3, ip, lr}
- bl user_enter
+ bl context_tracking_user_enter
ldmia sp!, {r0-r3, ip, lr}
.else
- bl user_enter
+ bl context_tracking_user_enter
.endif
#endif
.endm
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 247091bf058..859c8dfd78a 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -51,6 +51,15 @@ void context_tracking_user_enter(void)
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 static key
+ * check.
+ */
+ if (!static_key_false(&context_tracking_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()
@@ -151,6 +160,9 @@ void context_tracking_user_exit(void)
{
unsigned long flags;
+ if (!static_key_false(&context_tracking_enabled))
+ return;
+
if (in_interrupt())
return;