| Message ID | 52206E4E.6010507@huawei.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On 08/30/2013 12:05 PM, Ding Tianhong wrote: > remove the wordy int and add bond_for_each_slave_next_rcu() for future use. > > Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> > Cc: Nikolay Aleksandrov <nikolay@redhat.com> > --- > drivers/net/bonding/bond_alb.c | 3 +-- > drivers/net/bonding/bond_main.c | 6 ++---- > drivers/net/bonding/bonding.h | 19 +++++++++++++++---- > 3 files changed, 18 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c > index 3a5db7b..d266c56 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 4264a76..8c9902a 100644 > --- a/drivers/net/bonding/bond_main.c > +++ b/drivers/net/bonding/bond_main.c > @@ -904,7 +904,6 @@ 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; > > @@ -923,7 +922,7 @@ 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 && > @@ -2891,7 +2890,6 @@ do_failover: > static void bond_ab_arp_probe(struct bonding *bond) > { > struct slave *slave, *next_slave; > - int i; > > read_lock(&bond->curr_slave_lock); > > @@ -2923,7 +2921,7 @@ 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 9898493..a3ab47f 100644 > --- a/drivers/net/bonding/bonding.h > +++ b/drivers/net/bonding/bonding.h > @@ -119,14 +119,25 @@ > * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ > + cnt++, pos = bond_next_slave(bond, pos)) > + Please read below the argument against using the nested cnt definition. > +/** > + * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ > + cnt++, pos = bond_next_slave_rcu(bond, pos)) > I don't think you can rely on slave_cnt in RCU, you may go overboard and pass twice over the same slave if a slave gets removed, or the opposite. Also this definition of cnt is troublesome because the name is quite common, I don't know if it's accepted, but it if it is at least change the name to something like __cnt or anything that is less likely to be defined. The cnt argument goes for bond_for_each_slave_from as well. > /** > * bond_for_each_slave - iterate over all slaves > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013/9/3 18:22, Nikolay Aleksandrov wrote: > On 08/30/2013 12:05 PM, Ding Tianhong wrote: >> remove the wordy int and add bond_for_each_slave_next_rcu() for future use. >> >> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> >> Cc: Nikolay Aleksandrov <nikolay@redhat.com> >> --- >> drivers/net/bonding/bond_alb.c | 3 +-- >> drivers/net/bonding/bond_main.c | 6 ++---- >> drivers/net/bonding/bonding.h | 19 +++++++++++++++---- >> 3 files changed, 18 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c >> index 3a5db7b..d266c56 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 4264a76..8c9902a 100644 >> --- a/drivers/net/bonding/bond_main.c >> +++ b/drivers/net/bonding/bond_main.c >> @@ -904,7 +904,6 @@ 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; >> >> @@ -923,7 +922,7 @@ 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 && >> @@ -2891,7 +2890,6 @@ do_failover: >> static void bond_ab_arp_probe(struct bonding *bond) >> { >> struct slave *slave, *next_slave; >> - int i; >> >> read_lock(&bond->curr_slave_lock); >> >> @@ -2923,7 +2921,7 @@ 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 9898493..a3ab47f 100644 >> --- a/drivers/net/bonding/bonding.h >> +++ b/drivers/net/bonding/bonding.h >> @@ -119,14 +119,25 @@ >> * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ >> + cnt++, pos = bond_next_slave(bond, pos)) >> + > Please read below the argument against using the nested cnt definition. > >> +/** >> + * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ >> + cnt++, pos = bond_next_slave_rcu(bond, pos)) >> > I don't think you can rely on slave_cnt in RCU, you may go overboard and pass > twice over the same slave if a slave gets removed, or the opposite. Also this > definition of cnt is troublesome because the name is quite common, I don't know > if it's accepted, but it if it is at least change the name to something like > __cnt or anything that is less likely to be defined. > The cnt argument goes for bond_for_each_slave_from as well. > yes, more details need to think about, I modify the function to this: #define bond_for_each_slave_from(bond, pos, start) \ for (pos = start; (pos == bond_next_slave(bond, start) ? \ &pos->list != &bond->slave_list : \ &pos->list != &start->list); \ pos = bond_next_slave(bond, pos)) I think it is fine here, or I miss something, please tell me, thanks. :) >> /** >> * bond_for_each_slave - iterate over all slaves >> > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > . > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index 3a5db7b..d266c56 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 4264a76..8c9902a 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -904,7 +904,6 @@ 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; @@ -923,7 +922,7 @@ 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 && @@ -2891,7 +2890,6 @@ do_failover: static void bond_ab_arp_probe(struct bonding *bond) { struct slave *slave, *next_slave; - int i; read_lock(&bond->curr_slave_lock); @@ -2923,7 +2921,7 @@ 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 9898493..a3ab47f 100644 --- a/drivers/net/bonding/bonding.h +++ b/drivers/net/bonding/bonding.h @@ -119,14 +119,25 @@ * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ + cnt++, pos = bond_next_slave(bond, pos)) + +/** + * 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 (int cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \ + cnt++, pos = bond_next_slave_rcu(bond, pos)) /** * bond_for_each_slave - iterate over all slaves
remove the wordy int and add bond_for_each_slave_next_rcu() for future use. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Cc: Nikolay Aleksandrov <nikolay@redhat.com> --- drivers/net/bonding/bond_alb.c | 3 +-- drivers/net/bonding/bond_main.c | 6 ++---- drivers/net/bonding/bonding.h | 19 +++++++++++++++---- 3 files changed, 18 insertions(+), 10 deletions(-)