From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH 1/5] bonding: simplify and use RCU protection for 3ad xmit path Date: Thu, 29 Aug 2013 16:25:38 +0200 Message-ID: <521F59E2.8030707@redhat.com> References: <521D7A96.9070904@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Veaceslav Falico , Netdev To: Ding Tianhong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55969 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753001Ab3H2O30 (ORCPT ); Thu, 29 Aug 2013 10:29:26 -0400 In-Reply-To: <521D7A96.9070904@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On 08/28/2013 06:20 AM, Ding Tianhong wrote: > The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb > (bonding: initial RCU conversion) has convert the roundrobin, active-backup, > broadcast and xor xmit path to rcu protection, the performance will be better > for these mode, so this time, convert xmit path for 3ad mode. > > Signed-off-by: Ding Tianhong > Signed-off-by: Wang Yufen > Cc: Nikolay Aleksandrov > Cc: Veaceslav Falico > --- > drivers/net/bonding/bond_3ad.c | 31 +++++++++++++------------------ > drivers/net/bonding/bonding.h | 22 ++++++++++++++++++++++ > 2 files changed, 35 insertions(+), 18 deletions(-) > > diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c > index 9010265..52d76a4 100644 > --- a/drivers/net/bonding/bond_3ad.c > +++ b/drivers/net/bonding/bond_3ad.c > @@ -143,7 +143,7 @@ static inline struct bonding *__get_bond_by_port(struct port *port) > */ > static inline struct port *__get_first_port(struct bonding *bond) > { > - struct slave *first_slave = bond_first_slave(bond); > + struct slave *first_slave = bond_first_slave_rcu(bond); > > return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL; > } > @@ -163,7 +163,7 @@ static inline struct port *__get_next_port(struct port *port) > // If there's no bond for this port, or this is the last slave > if (bond == NULL) > return NULL; > - slave_next = bond_next_slave(bond, slave); > + slave_next = bond_next_slave_rcu(bond, slave); > if (!slave_next || bond_is_first_slave(bond, slave_next)) > return NULL; > > @@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info) > > int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) > { > - struct slave *slave, *start_at; > + struct slave *slave; Please re-arrange longest -> shortest where possible. > struct bonding *bond = netdev_priv(dev); > int slave_agg_no; > int slaves_in_agg; > int agg_id; > - int i; > struct ad_info ad_info; > int res = 1; > > - read_lock(&bond->lock); > if (__bond_3ad_get_active_agg_info(bond, &ad_info)) { > pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n", > dev->name); > @@ -2444,13 +2442,16 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) > > slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg); > > - bond_for_each_slave(bond, slave) { > + bond_for_each_slave_rcu(bond, slave) { > struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator; > > if (agg && (agg->aggregator_identifier == agg_id)) { > - slave_agg_no--; > - if (slave_agg_no < 0) > - break; > + if (--slave_agg_no < 0) { > + if (SLAVE_IS_OK(slave)) { > + res = bond_dev_queue_xmit(bond, skb, slave->dev); > + goto out; > + } > + } > } > } > > @@ -2460,23 +2461,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) > goto out; > } > > - start_at = slave; > - > - bond_for_each_slave_from(bond, slave, i, start_at) { > - int slave_agg_id = 0; > + bond_for_each_slave_rcu(bond, slave) { > struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator; > > - if (agg) > - slave_agg_id = agg->aggregator_identifier; > - > - if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) { > + if (SLAVE_IS_OK(slave) && agg && > + (agg->aggregator_identifier == agg_id)) { Please drop the ( ) from (agg->aggregator_identifier == agg_id), also align it properly. > res = bond_dev_queue_xmit(bond, skb, slave->dev); > break; > } > } > > out: > - read_unlock(&bond->lock); > if (res) { > /* no suitable interface, frame not sent */ > kfree_skb(skb); > diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h > index 4bf52d5..ecb5d1d 100644 > --- a/drivers/net/bonding/bonding.h > +++ b/drivers/net/bonding/bonding.h > @@ -74,6 +74,9 @@ > /* slave list primitives */ > #define bond_to_slave(ptr) list_entry(ptr, struct slave, list) > > +/* slave list primitives, Caller must hold rcu_read_lock */ > +#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list) > + > /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */ > #define bond_first_slave(bond) \ > list_first_entry_or_null(&(bond)->slave_list, struct slave, list) > @@ -81,6 +84,16 @@ > (list_empty(&(bond)->slave_list) ? NULL : \ > bond_to_slave((bond)->slave_list.prev)) > > +/** > + * IMPORTANT: bond_first/last_slave_rcu can return NULL in case of an empty list > + * Caller must hold rcu_read_lock > + */ Styling nit: the comments in net/ should be /* text... > +#define bond_first_slave_rcu(bond) \ > + list_first_or_null_rcu(&(bond)->slave_list, struct slave, list) > +#define bond_last_slave_rcu(bond) \ > + (list_emptry(&(bond)->slave_list) ? NULL : \ ^^^^^^^^^^^^^^^^^^^^^ Did you compile this ? > + bond_to_slave_rcu((bond)->slave_list.prev)) > + > #define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list) > #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list) > > @@ -93,6 +106,15 @@ > (bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \ > bond_to_slave((pos)->list.prev)) > > +/* Since bond_first/last_slave_rcu can return NULL, these can return NULL too */ > +#define bond_next_slave_rcu(bond, pos) \ > + (bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \ > + bond_to_slave_rcu((pos)->list.next)) > + > +#define bond_prev_slave_rcu(bond, pos) \ > + (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \ > + bond_to_slave_rcu((pos)->list.prev)) > + > /** > * bond_for_each_slave_from - iterate the slaves list from a starting point > * @bond: the bond holding this list. >