From 28aecb9d7728dc26bf03ce7925fe622023a83a2a Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 29 Jan 2010 04:05:52 +0000
Subject: xfrm: avoid spinlock in get_acqseq()
Use atomic_inc_return() in get_acqseq() to avoid taking a spinlock
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/key/af_key.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
(limited to 'net')
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 4744b1f6372f..e2aacf0ba013 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3019,12 +3019,11 @@ static int pfkey_send_policy_notify(struct xfrm_policy *xp, int dir, struct km_e
static u32 get_acqseq(void)
{
u32 res;
- static u32 acqseq;
- static DEFINE_SPINLOCK(acqseq_lock);
+ static atomic_t acqseq;
- spin_lock_bh(&acqseq_lock);
- res = (++acqseq ? : ++acqseq);
- spin_unlock_bh(&acqseq_lock);
+ do {
+ res = atomic_inc_return(&acqseq);
+ } while (!res);
return res;
}
--
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