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lglock: remove online variants of lock

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Optimizing the slow paths adds a lot of complexity.  If you need to
grab every lock often, you have other problems.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Rusty Russell 2012-05-08 13:29:45 +09:30 committed by Al Viro
parent ea022dfb3c
commit 9dd6fa03ab
1 changed files with 2 additions and 56 deletions
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58
include/linux/lglock.h
View file

@ -28,8 +28,8 @@
#define br_lock_init(name) name##_lock_init()
#define br_read_lock(name) name##_local_lock()
#define br_read_unlock(name) name##_local_unlock()
#define br_write_lock(name) name##_global_lock_online()
#define br_write_unlock(name) name##_global_unlock_online()
#define br_write_lock(name) name##_global_lock()
#define br_write_unlock(name) name##_global_unlock()
#define DECLARE_BRLOCK(name) DECLARE_LGLOCK(name)
#define DEFINE_BRLOCK(name) DEFINE_LGLOCK(name)
@ -42,8 +42,6 @@
#define lg_local_unlock_cpu(name, cpu) name##_local_unlock_cpu(cpu)
#define lg_global_lock(name) name##_global_lock()
#define lg_global_unlock(name) name##_global_unlock()
#define lg_global_lock_online(name) name##_global_lock_online()
#define lg_global_unlock_online(name) name##_global_unlock_online()
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define LOCKDEP_INIT_MAP lockdep_init_map
@ -68,36 +66,13 @@
extern void name##_local_unlock_cpu(int cpu); \
extern void name##_global_lock(void); \
extern void name##_global_unlock(void); \
extern void name##_global_lock_online(void); \
extern void name##_global_unlock_online(void); \
#define DEFINE_LGLOCK(name) \
\
DEFINE_SPINLOCK(name##_cpu_lock); \
cpumask_t name##_cpus __read_mostly; \
DEFINE_PER_CPU(arch_spinlock_t, name##_lock); \
DEFINE_LGLOCK_LOCKDEP(name); \
\
static int \
name##_lg_cpu_callback(struct notifier_block *nb, \
unsigned long action, void *hcpu) \
{ \
switch (action & ~CPU_TASKS_FROZEN) { \
case CPU_UP_PREPARE: \
spin_lock(&name##_cpu_lock); \
cpu_set((unsigned long)hcpu, name##_cpus); \
spin_unlock(&name##_cpu_lock); \
break; \
case CPU_UP_CANCELED: case CPU_DEAD: \
spin_lock(&name##_cpu_lock); \
cpu_clear((unsigned long)hcpu, name##_cpus); \
spin_unlock(&name##_cpu_lock); \
} \
return NOTIFY_OK; \
} \
static struct notifier_block name##_lg_cpu_notifier = { \
.notifier_call = name##_lg_cpu_callback, \
}; \
void name##_lock_init(void) { \
int i; \
LOCKDEP_INIT_MAP(&name##_lock_dep_map, #name, &name##_lock_key, 0); \
@ -106,11 +81,6 @@
lock = &per_cpu(name##_lock, i); \
*lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; \
} \
register_hotcpu_notifier(&name##_lg_cpu_notifier); \
get_online_cpus(); \
for_each_online_cpu(i) \
cpu_set(i, name##_cpus); \
put_online_cpus(); \
} \
EXPORT_SYMBOL(name##_lock_init); \
\
@ -150,30 +120,6 @@
} \
EXPORT_SYMBOL(name##_local_unlock_cpu); \
\
void name##_global_lock_online(void) { \
int i; \
spin_lock(&name##_cpu_lock); \
rwlock_acquire(&name##_lock_dep_map, 0, 0, _RET_IP_); \
for_each_cpu(i, &name##_cpus) { \
arch_spinlock_t *lock; \
lock = &per_cpu(name##_lock, i); \
arch_spin_lock(lock); \
} \
} \
EXPORT_SYMBOL(name##_global_lock_online); \
\
void name##_global_unlock_online(void) { \
int i; \
rwlock_release(&name##_lock_dep_map, 1, _RET_IP_); \
for_each_cpu(i, &name##_cpus) { \
arch_spinlock_t *lock; \
lock = &per_cpu(name##_lock, i); \
arch_spin_unlock(lock); \
} \
spin_unlock(&name##_cpu_lock); \
} \
EXPORT_SYMBOL(name##_global_unlock_online); \
\
void name##_global_lock(void) { \
int i; \
preempt_disable(); \