[PATCH] netfilter: nf_conntrack: consolidate lock/unlock into unlock_wait

From: Nicholas Mc Guire
Date: Mon Mar 14 2016 - 07:44:43 EST


The spin_lock()/spin_unlock() is synchronizing on the
nf_conntrack_locks_all_lock which is equivalent to
spin_unlock_wait() but the later should be more efficient.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
---

Patch was compile tested with: x86_64_defconfig (implies CONFIG_NETFILTER=y)
Simple run test on x86 64 with a few trivial ipfilter rules active.

Patch is against linux-next (localversion-next is next-20160311)

net/netfilter/nf_conntrack_core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f60b4fd..afde5f5 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -74,8 +74,7 @@ void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
spin_lock(lock);
while (unlikely(nf_conntrack_locks_all)) {
spin_unlock(lock);
- spin_lock(&nf_conntrack_locks_all_lock);
- spin_unlock(&nf_conntrack_locks_all_lock);
+ spin_unlock_wait(&nf_conntrack_locks_all_lock);
spin_lock(lock);
}
}
@@ -121,8 +120,7 @@ static void nf_conntrack_all_lock(void)
nf_conntrack_locks_all = true;

for (i = 0; i < CONNTRACK_LOCKS; i++) {
- spin_lock(&nf_conntrack_locks[i]);
- spin_unlock(&nf_conntrack_locks[i]);
+ spin_unlock_wait(&nf_conntrack_locks[i]);
}
}

--
2.1.4