From 95c354fe9f7d6decc08a92aa26eb233ecc2155bf Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 30 Jan 2008 13:31:20 +0100 Subject: spinlock: lockbreak cleanup The break_lock data structure and code for spinlocks is quite nasty. Not only does it double the size of a spinlock but it changes locking to a potentially less optimal trylock. Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a __raw_spin_is_contended that uses the lock data itself to determine whether there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is not set. Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to decouple it from the spinlock implementation, and make it typesafe (rwlocks do not have any need_lockbreak sites -- why do they even get bloated up with that break_lock then?). Signed-off-by: Nick Piggin Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/spinlock_types.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/spinlock_types.h') diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h index f6a3a951b79..68d88f71f1a 100644 --- a/include/linux/spinlock_types.h +++ b/include/linux/spinlock_types.h @@ -19,7 +19,7 @@ typedef struct { raw_spinlock_t raw_lock; -#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) +#ifdef CONFIG_GENERIC_LOCKBREAK unsigned int break_lock; #endif #ifdef CONFIG_DEBUG_SPINLOCK @@ -35,7 +35,7 @@ typedef struct { typedef struct { raw_rwlock_t raw_lock; -#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) +#ifdef CONFIG_GENERIC_LOCKBREAK unsigned int break_lock; #endif #ifdef CONFIG_DEBUG_SPINLOCK -- cgit v1.2.3