From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next-2.6] igmp: Use next_net_device_rcu() Date: Thu, 12 Nov 2009 04:48:52 +0100 Message-ID: <4AFB85A4.1050408@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Linux Netdev List , Stephen Hemminger To: "David S. Miller" Return-path: Received: from gw1.cosmosbay.com ([212.99.114.194]:57913 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751812AbZKLDsw (ORCPT ); Wed, 11 Nov 2009 22:48:52 -0500 Sender: netdev-owner@vger.kernel.org List-ID: We need to use next_det_device_rcu() in RCU protected section. We also can avoid in_dev_get()/in_dev_put() overhead (code size mainly) in rcu_read_lock() sections. Signed-off-by: Eric Dumazet --- net/ipv4/igmp.c | 27 +++++++++++---------------- 1 files changed, 11 insertions(+), 16 deletions(-) diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index bd24f65..6110c6d 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -2313,7 +2313,8 @@ static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq) state->in_dev = NULL; for_each_netdev_rcu(net, state->dev) { struct in_device *in_dev; - in_dev = in_dev_get(state->dev); + + in_dev = __in_dev_get_rcu(state->dev); if (!in_dev) continue; read_lock(&in_dev->mc_list_lock); @@ -2323,7 +2324,6 @@ static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq) break; } read_unlock(&in_dev->mc_list_lock); - in_dev_put(in_dev); } return im; } @@ -2333,16 +2333,15 @@ static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_li struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); im = im->next; while (!im) { - if (likely(state->in_dev != NULL)) { + if (likely(state->in_dev != NULL)) read_unlock(&state->in_dev->mc_list_lock); - in_dev_put(state->in_dev); - } - state->dev = next_net_device(state->dev); + + state->dev = next_net_device_rcu(state->dev); if (!state->dev) { state->in_dev = NULL; break; } - state->in_dev = in_dev_get(state->dev); + state->in_dev = __in_dev_get_rcu(state->dev); if (!state->in_dev) continue; read_lock(&state->in_dev->mc_list_lock); @@ -2384,7 +2383,6 @@ static void igmp_mc_seq_stop(struct seq_file *seq, void *v) struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq); if (likely(state->in_dev != NULL)) { read_unlock(&state->in_dev->mc_list_lock); - in_dev_put(state->in_dev); state->in_dev = NULL; } state->dev = NULL; @@ -2464,7 +2462,7 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq) state->im = NULL; for_each_netdev_rcu(net, state->dev) { struct in_device *idev; - idev = in_dev_get(state->dev); + idev = __in_dev_get_rcu(state->dev); if (unlikely(idev == NULL)) continue; read_lock(&idev->mc_list_lock); @@ -2480,7 +2478,6 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq) spin_unlock_bh(&im->lock); } read_unlock(&idev->mc_list_lock); - in_dev_put(idev); } return psf; } @@ -2494,16 +2491,15 @@ static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_l spin_unlock_bh(&state->im->lock); state->im = state->im->next; while (!state->im) { - if (likely(state->idev != NULL)) { + if (likely(state->idev != NULL)) read_unlock(&state->idev->mc_list_lock); - in_dev_put(state->idev); - } - state->dev = next_net_device(state->dev); + + state->dev = next_net_device_rcu(state->dev); if (!state->dev) { state->idev = NULL; goto out; } - state->idev = in_dev_get(state->dev); + state->idev = __in_dev_get_rcu(state->dev); if (!state->idev) continue; read_lock(&state->idev->mc_list_lock); @@ -2555,7 +2551,6 @@ static void igmp_mcf_seq_stop(struct seq_file *seq, void *v) } if (likely(state->idev != NULL)) { read_unlock(&state->idev->mc_list_lock); - in_dev_put(state->idev); state->idev = NULL; } state->dev = NULL;