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

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

[Nicholas Mc Guire]

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@osadl.org>
---

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

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

[Pablo Neira Ayuso]

On Mon, Mar 14, 2016 at 12:39:02PM +0100, Nicholas Mc Guire wrote:
> 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.

Applied, thanks.