From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH ipsec-next] xfrm: state lookup can be lockless Date: Tue, 20 Sep 2016 15:45:26 +0200 Message-ID: <1474379126-32550-1-git-send-email-fw@strlen.de> Cc: Florian Westphal To: Return-path: Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:32962 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752364AbcITNpN (ORCPT ); Tue, 20 Sep 2016 09:45:13 -0400 Sender: netdev-owner@vger.kernel.org List-ID: This is called from the packet input path, we get lock contention if many cpus handle ipsec in parallel. After recent rcu conversion it is safe to call __xfrm_state_lookup without the spinlock. Signed-off-by: Florian Westphal --- net/xfrm/xfrm_state.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index ba8bf51..a38fdea 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -1431,9 +1431,9 @@ xfrm_state_lookup(struct net *net, u32 mark, const xfrm_address_t *daddr, __be32 { struct xfrm_state *x; - spin_lock_bh(&net->xfrm.xfrm_state_lock); + rcu_read_lock(); x = __xfrm_state_lookup(net, mark, daddr, spi, proto, family); - spin_unlock_bh(&net->xfrm.xfrm_state_lock); + rcu_read_unlock(); return x; } EXPORT_SYMBOL(xfrm_state_lookup); -- 2.7.3