From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [PATCH net-next v3 1/6] bonding: simplify and use RCU protection for 3ad xmit path Date: Thu, 5 Sep 2013 15:42:58 +0200 Message-ID: <20130905134258.GB26163@redhat.com> References: <5228375C.1050105@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Nikolay Aleksandrov , Netdev To: Ding Tianhong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:17484 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820Ab3IENok (ORCPT ); Thu, 5 Sep 2013 09:44:40 -0400 Content-Disposition: inline In-Reply-To: <5228375C.1050105@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Sep 05, 2013 at 03:48:44PM +0800, 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. > >Suggested-by: Nikolay Aleksandrov >Suggested-by: Veaceslav Falico >Signed-off-by: Ding Tianhong >Signed-off-by: Wang Yufen >Cc: Nikolay Aleksandrov >Cc: Veaceslav Falico >--- > drivers/net/bonding/bond_3ad.c | 32 ++++++++++++++------------------ > drivers/net/bonding/bonding.h | 32 +++++++++++++++++++++++++++++++- > 2 files changed, 45 insertions(+), 19 deletions(-) > >diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >index 0d8f427..13f1deb 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 bonding *bond = netdev_priv(dev); >+ struct slave *slave; > 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 +2442,17 @@ 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 +2462,17 @@ 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) { > 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 f7ab161..f013b12 100644 >--- a/drivers/net/bonding/bonding.h >+++ b/drivers/net/bonding/bonding.h >@@ -74,13 +74,34 @@ > /* 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) >+ >+/* bond_is_empty return NULL if slave list is empty*/ >+#define bond_is_empty(bond) \ >+ (list_empty(&(bond)->slave_list)) >+ >+/* bond_is_empty_rcu return NULL if slave list is empty*/ >+#define bond_is_empty_rcu(bond) \ >+ (!list_first_or_null_rcu(&(bond)->slave_list, 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) > #define bond_last_slave(bond) \ >- (list_empty(&(bond)->slave_list) ? NULL : \ >+ (bond_is_empty(bond) ? 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 >+ */ >+#define bond_first_slave_rcu(bond) \ >+ list_first_or_null_rcu(&(bond)->slave_list, struct slave, list) >+#define bond_last_slave_rcu(bond) \ >+ (bond_is_empty_rcu(bond) ? NULL : \ >+ bond_to_slave_rcu((bond)->slave_list.prev)) Really? No. Again - take a look at list_first_or_null_rcu. And its comments. I'm sorry that I'm acting that negatively... But if that gets accepted - I'll have days of nightmares. Try to understand how RCU works, please, before sending patches using it. >+ > #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 +114,15 @@ > (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. >-- >1.8.2.1 > > >