From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [PATCH net-next v3 5/6] bonding: restructure and add rcu for bond_for_each_slave_next() Date: Thu, 5 Sep 2013 15:30:27 +0200 Message-ID: <20130905133027.GA26163@redhat.com> References: <5228376D.2040608@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]:53498 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750708Ab3IENcM (ORCPT ); Thu, 5 Sep 2013 09:32:12 -0400 Content-Disposition: inline In-Reply-To: <5228376D.2040608@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Sep 05, 2013 at 03:49:01PM +0800, Ding Tianhong wrote: >Remove the wordy int and add bond_for_each_slave_next_rcu() for future use. > >Suggested-by: Nikolay Aleksandrov >Suggested-by: Veaceslav Falico >Signed-off-by: Ding Tianhong >Cc: Nikolay Aleksandrov >Cc: Veaceslav Falico >--- > drivers/net/bonding/bond_alb.c | 3 +-- > drivers/net/bonding/bond_main.c | 6 ++---- > drivers/net/bonding/bonding.h | 23 +++++++++++++++++++---- > 3 files changed, 22 insertions(+), 10 deletions(-) > >diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c >index 91f179d..c75d383 100644 >--- a/drivers/net/bonding/bond_alb.c >+++ b/drivers/net/bonding/bond_alb.c >@@ -383,7 +383,6 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond) > { > struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond)); > struct slave *rx_slave, *slave, *start_at; >- int i = 0; > > if (bond_info->next_rx_slave) > start_at = bond_info->next_rx_slave; >@@ -392,7 +391,7 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond) > > rx_slave = NULL; > >- bond_for_each_slave_from(bond, slave, i, start_at) { >+ bond_for_each_slave_from(bond, slave, start_at) { > if (SLAVE_IS_OK(slave)) { > if (!rx_slave) { > rx_slave = slave; >diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c >index 39e5b1c..4190389 100644 >--- a/drivers/net/bonding/bond_main.c >+++ b/drivers/net/bonding/bond_main.c >@@ -782,7 +782,6 @@ static struct slave *bond_find_best_slave(struct bonding *bond) > struct slave *new_active, *old_active; > struct slave *bestslave = NULL; > int mintime = bond->params.updelay; >- int i; > > new_active = bond->curr_active_slave; > >@@ -801,7 +800,7 @@ static struct slave *bond_find_best_slave(struct bonding *bond) > /* remember where to stop iterating over the slaves */ > old_active = new_active; > >- bond_for_each_slave_from(bond, new_active, i, old_active) { >+ bond_for_each_slave_from(bond, new_active, old_active) { > if (new_active->link == BOND_LINK_UP) { > return new_active; > } else if (new_active->link == BOND_LINK_BACK && >@@ -2756,7 +2755,6 @@ do_failover: > static void bond_ab_arp_probe(struct bonding *bond) > { > struct slave *slave, *next_slave; >- int i; > > read_lock(&bond->curr_slave_lock); > >@@ -2788,7 +2786,7 @@ static void bond_ab_arp_probe(struct bonding *bond) > > /* search for next candidate */ > next_slave = bond_next_slave(bond, bond->current_arp_slave); >- bond_for_each_slave_from(bond, slave, i, next_slave) { >+ bond_for_each_slave_from(bond, slave, next_slave) { > if (IS_UP(slave->dev)) { > slave->link = BOND_LINK_BACK; > bond_set_slave_active_flags(slave); >diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h >index f013b12..48fd41a 100644 >--- a/drivers/net/bonding/bonding.h >+++ b/drivers/net/bonding/bonding.h >@@ -123,18 +123,33 @@ > (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \ > bond_to_slave_rcu((pos)->list.prev)) > >+/* Check whether the slave is the only one in bond */ >+ > /** > * bond_for_each_slave_from - iterate the slaves list from a starting point > * @bond: the bond holding this list. > * @pos: current slave. >- * @cnt: counter for max number of moves > * @start: starting point. > * > * Caller must hold bond->lock > */ >-#define bond_for_each_slave_from(bond, pos, cnt, start) \ >- for (cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ >- cnt++, pos = bond_next_slave(bond, pos)) >+#define bond_for_each_slave_from(bond, pos, start) \ >+ for (pos = start; pos && &pos->list != &bond->slave_list; \ >+ (pos = bond_next_slave(bond, pos)) != start ? pos : \ >+ (pos = list_entry(&bond->slave_list, typeof(*pos), list))) Do you understand the differences of these two implementations? pos && cnt < (bond)->slave_cnt vs pos && &pos->list != &bond->slave_list I'm sorry, but you should listen to comments. >+ >+/** >+ * bond_for_each_slave_from_rcu - iterate the slaves list from a starting point >+ * @bond: the bond holding this list. >+ * @pos: current slave. >+ * @start: starting point. >+ * >+ * Caller must hold rcu_read_lock >+ */ >+#define bond_for_each_slave_from_rcu(bond, pos, start) \ >+ for (pos = start; pos && &pos->list != &bond->slave_list; \ >+ (pos = bond_next_slave_rcu(bond, pos)) != start ? pos : \ >+ (pos = list_entry_rcu(&bond->slave_list, typeof(*pos), list))) > > /** > * bond_for_each_slave - iterate over all slaves >-- >1.8.2.1 > > >