From: Shan Hai <haishan.bai@gmail.com>
To: akpm@linux-foundation.org
Cc: eric.dumazet@gmail.com, vapier@gentoo.org, asharma@fb.com,
linux-kernel@vger.kernel.org, Shan Hai <haishan.bai@gmail.com>
Subject: [PATCH 1/1] lib:atomic64 using raw_spin_lock_irq[save|resotre] for atomicity
Date: Thu, 1 Sep 2011 09:28:00 +0800 [thread overview]
Message-ID: <1314840480-25182-2-git-send-email-haishan.bai@gmail.com> (raw)
In-Reply-To: <1314840480-25182-1-git-send-email-haishan.bai@gmail.com>
The spin_lock_irq[save|restore] could break the atomicity of the
atomic64_* operations in the PREEMPT-RT configuration, because
the spin_lock_irq[save|restore] themselves are preemptable in the
PREEMPT-RT, using raw variant of the spin lock could provide the
atomicity that atomic64_* need.
Signed-off-by: Shan Hai <haishan.bai@gmail.com>
---
lib/atomic64.c | 40 ++++++++++++++++++++--------------------
1 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/lib/atomic64.c b/lib/atomic64.c
index e12ae0d..26f524a 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -48,9 +48,9 @@ long long atomic64_read(const atomic64_t *v)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_read);
@@ -60,9 +60,9 @@ void atomic64_set(atomic64_t *v, long long i)
unsigned long flags;
spinlock_t *lock = lock_addr(v);
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
v->counter = i;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(atomic64_set);
@@ -71,9 +71,9 @@ void atomic64_add(long long a, atomic64_t *v)
unsigned long flags;
spinlock_t *lock = lock_addr(v);
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
v->counter += a;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(atomic64_add);
@@ -83,9 +83,9 @@ long long atomic64_add_return(long long a, atomic64_t *v)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter += a;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_add_return);
@@ -95,9 +95,9 @@ void atomic64_sub(long long a, atomic64_t *v)
unsigned long flags;
spinlock_t *lock = lock_addr(v);
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
v->counter -= a;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(atomic64_sub);
@@ -107,9 +107,9 @@ long long atomic64_sub_return(long long a, atomic64_t *v)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter -= a;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_sub_return);
@@ -120,11 +120,11 @@ long long atomic64_dec_if_positive(atomic64_t *v)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter - 1;
if (val >= 0)
v->counter = val;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_dec_if_positive);
@@ -135,11 +135,11 @@ long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter;
if (val == o)
v->counter = n;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_cmpxchg);
@@ -150,10 +150,10 @@ long long atomic64_xchg(atomic64_t *v, long long new)
spinlock_t *lock = lock_addr(v);
long long val;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
val = v->counter;
v->counter = new;
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return val;
}
EXPORT_SYMBOL(atomic64_xchg);
@@ -164,12 +164,12 @@ int atomic64_add_unless(atomic64_t *v, long long a, long long u)
spinlock_t *lock = lock_addr(v);
int ret = 0;
- spin_lock_irqsave(lock, flags);
+ raw_spin_lock_irqsave(lock, flags);
if (v->counter != u) {
v->counter += a;
ret = 1;
}
- spin_unlock_irqrestore(lock, flags);
+ raw_spin_unlock_irqrestore(lock, flags);
return ret;
}
EXPORT_SYMBOL(atomic64_add_unless);
--
1.7.4.1
next prev parent reply other threads:[~2011-09-01 1:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 1:27 [PATCH 0/1] " Shan Hai
2011-09-01 1:28 ` Shan Hai [this message]
2011-09-01 2:37 ` [PATCH 1/1 -rt] " Yong Zhang
2011-09-01 3:02 ` Shan Hai
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