lkml.org 
[lkml]   [2018]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 5/5] locking/lockdep: Call lock_release() after releasing the lock
Date
Currently, lock_acquire() is called before acquiring the lock and
lock_release() is called before the releasing the lock. As a result,
the execution time of lock_release() is added to the lock hold time
reducing locking throughput, especially for spinlocks and rwlocks which
tend to have a much shorter lock hold time.

As lock_release() is not going to update any shared data that needs
protection from the lock, we don't actually need to call it before
releasing the lock. So the lock_release() calls are now postponed to
after releasing the lock for spinlocks and rwlocks.

Signed-off-by: Waiman Long <longman@redhat.com>
---
include/linux/rwlock_api_smp.h | 16 ++++++++--------
include/linux/spinlock_api_smp.h | 8 ++++----
2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index 86ebb4bf9c6e..b026940a0962 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -215,63 +215,63 @@ static inline void __raw_write_lock(rwlock_t *lock)

static inline void __raw_write_unlock(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_write_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
preempt_enable();
}

static inline void __raw_read_unlock(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_read_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
preempt_enable();
}

static inline void
__raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_read_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
local_irq_restore(flags);
preempt_enable();
}

static inline void __raw_read_unlock_irq(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_read_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
local_irq_enable();
preempt_enable();
}

static inline void __raw_read_unlock_bh(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_read_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
__local_bh_enable_ip(_RET_IP_, SOFTIRQ_LOCK_OFFSET);
}

static inline void __raw_write_unlock_irqrestore(rwlock_t *lock,
unsigned long flags)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_write_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
local_irq_restore(flags);
preempt_enable();
}

static inline void __raw_write_unlock_irq(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_write_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
local_irq_enable();
preempt_enable();
}

static inline void __raw_write_unlock_bh(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
do_raw_write_unlock(lock);
+ rwlock_release(&lock->dep_map, 1, _RET_IP_);
__local_bh_enable_ip(_RET_IP_, SOFTIRQ_LOCK_OFFSET);
}

diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index 42dfab89e740..fcb84df0678b 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -147,32 +147,32 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock)

static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
do_raw_spin_unlock(lock);
+ spin_release(&lock->dep_map, 1, _RET_IP_);
preempt_enable();
}

static inline void __raw_spin_unlock_irqrestore(raw_spinlock_t *lock,
unsigned long flags)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
do_raw_spin_unlock(lock);
+ spin_release(&lock->dep_map, 1, _RET_IP_);
local_irq_restore(flags);
preempt_enable();
}

static inline void __raw_spin_unlock_irq(raw_spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
do_raw_spin_unlock(lock);
+ spin_release(&lock->dep_map, 1, _RET_IP_);
local_irq_enable();
preempt_enable();
}

static inline void __raw_spin_unlock_bh(raw_spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
do_raw_spin_unlock(lock);
+ spin_release(&lock->dep_map, 1, _RET_IP_);
__local_bh_enable_ip(_RET_IP_, SOFTIRQ_LOCK_OFFSET);
}

--
2.18.0
\
 
 \ /
  Last update: 2018-10-02 22:21    [W:0.056 / U:2.724 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site