[PATCH [RT] 11/14] optimize the !printk fastpath through the lockacquisition

From: Gregory Haskins
Date: Thu Feb 21 2008 - 11:00:10 EST


Decorate the printk path with an "unlikely()"

Signed-off-by: Gregory Haskins <ghaskins@xxxxxxxxxx>
---

kernel/rtmutex.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 122f143..ebdaa17 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -660,12 +660,12 @@ rt_spin_lock_fastlock(struct rt_mutex *lock,
void fastcall (*slowfn)(struct rt_mutex *lock))
{
/* Temporary HACK! */
- if (!current->in_printk)
- might_sleep();
- else if (in_atomic() || irqs_disabled())
+ if (unlikely(current->in_printk) && (in_atomic() || irqs_disabled()))
/* don't grab locks for printk in atomic */
return;

+ might_sleep();
+
if (likely(rt_mutex_cmpxchg(lock, NULL, current)))
rt_mutex_deadlock_account_lock(lock, current);
else
@@ -677,7 +677,7 @@ rt_spin_lock_fastunlock(struct rt_mutex *lock,
void fastcall (*slowfn)(struct rt_mutex *lock))
{
/* Temporary HACK! */
- if (current->in_printk && (in_atomic() || irqs_disabled()))
+ if (unlikely(current->in_printk) && (in_atomic() || irqs_disabled()))
/* don't grab locks for printk in atomic */
return;


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