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Message-ID: <533A962A.3090303@redhat.com>
Date: Tue, 01 Apr 2014 12:34:18 +0200
From: Nikolay Aleksandrov <nikolay@...hat.com>
To: Mahesh Bandewar <maheshb@...gle.com>,
Jay Vosburgh <fubar@...ibm.com>,
Veaceslav Falico <vfalico@...hat.com>,
Andy Gospodarek <andy@...yhouse.net>,
David Miller <davem@...emloft.net>
CC: netdev <netdev@...r.kernel.org>,
Eric Dumazet <edumazet@...gle.com>,
Maciej Zenczykowski <maze@...gle.com>
Subject: Re: [PATCH 5/5] bonding: Add tlb_dynamic_lb module parameter
On 03/29/2014 06:29 AM, Mahesh Bandewar wrote:
> The aggresive load balancing causes packet re-ordering as active
> flows are moved from a slave to another within the group. Sometime
> this aggresive lb is not necessary if the preference is for less
> re-ordering. This module parameter if used with value "0" disables
> this dynamic flow shuffling minimizing packet re-ordering. Of course
> the side effect is that it has to live with the static load balancing
> that the hashing distribution provides. This impact is less severe if
> the correct xmit-hashing-policy is used for the tlb setup.
>
> The default value of the parameter is set to "1" mimicing the earlier
> behavior.
>
> Ran the netperf test with 200 stream for 1 min between two hosts with
> 4x1G trunk (xmit-lb mode with xmit-policy L3+4) before and after these
> changes. Following was the command used for those 200 instances -
>
> netperf -t TCP_RR -l 60 -s 5 -H <host> -- -r1,1024
>
> Transactions per second:
> Before changes: 109250
> After changes: 113752
>
> Signed-off-by: Mahesh Bandewar <maheshb@...gle.com>
> ---
> drivers/net/bonding/bond_alb.c | 18 ++++++++++++++----
> drivers/net/bonding/bond_main.c | 28 +++++++++++++++++++++++++---
> drivers/net/bonding/bond_options.c | 31 +++++++++++++++++++++++++++++++
> drivers/net/bonding/bond_options.h | 1 +
> drivers/net/bonding/bond_sysfs.c | 29 +++++++++++++++++++++++++++++
> drivers/net/bonding/bonding.h | 1 +
> 6 files changed, 101 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 8b7426ce6182..fb79971b9d75 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -1356,7 +1356,8 @@ static int bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond,
> if (!tx_slave) {
> /* unbalanced or unassigned, send through primary */
> tx_slave = rcu_dereference(bond->curr_active_slave);
> - bond_info->unbalanced_load += skb->len;
> + if (bond->params.tlb_dynamic_lb)
> + bond_info->unbalanced_load += skb->len;
> }
>
> if (tx_slave && SLAVE_IS_OK(tx_slave)) {
> @@ -1369,7 +1370,7 @@ static int bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond,
> goto out;
> }
>
> - if (tx_slave) {
> + if (tx_slave && bond->params.tlb_dynamic_lb) {
> _lock_tx_hashtbl(bond);
> __tlb_clear_slave(bond, tx_slave, 0);
> _unlock_tx_hashtbl(bond);
> @@ -1398,11 +1399,20 @@ int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
> case ETH_P_IPX: /* In case of IPX, it will falback to L2 hash */
> case ETH_P_IPV6:
> hash_index = bond_xmit_hash(bond, skb);
> - tx_slave = tlb_choose_channel(bond, hash_index & 0xFF, skb->len);
> + if (bond->params.tlb_dynamic_lb) {
> + tx_slave = tlb_choose_channel(bond,
> + hash_index & 0xFF,
> + skb->len);
> + } else {
> + struct list_head *iter;
> + int idx = hash_index % bond->slave_cnt;
Small nit: please leave an empty line after the variable declarations.
> + bond_for_each_slave_rcu(bond, tx_slave, iter)
> + if (--idx < 0)
> + break;
> + }
> break;
> }
> }
> -
> return bond_do_alb_xmit(skb, bond, tx_slave);
> }
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 23e4073ec798..c122172c4e8c 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -111,6 +111,7 @@ static struct bond_params bonding_defaults;
> static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;
> static int packets_per_slave = 1;
> static int lp_interval = BOND_ALB_DEFAULT_LP_INTERVAL;
> +static int tlb_dynamic_lb = 1;
>
> module_param(max_bonds, int, 0);
> MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
> @@ -191,6 +192,9 @@ module_param(lp_interval, uint, 0);
> MODULE_PARM_DESC(lp_interval, "The number of seconds between instances where "
> "the bonding driver sends learning packets to "
> "each slaves peer switch. The default is 1.");
> +module_param(tlb_dynamic_lb, int, 0644);
> +MODULE_PARM_DESC(tlb_dynamic_lb, "Enable periodic flow balancing. "
> + "The default is 1.");
>
> /*----------------------------- Global variables ----------------------------*/
>
> @@ -3046,7 +3050,7 @@ static void bond_work_init_all(struct bonding *bond)
> {
> INIT_DELAYED_WORK(&bond->mcast_work,
> bond_resend_igmp_join_requests_delayed);
> - if (bond_is_lb(bond))
> + if (bond_is_lb(bond) && bond->params.tlb_dynamic_lb)
> INIT_DELAYED_WORK(&bond->alb_work, bond_alb_monitor);
> INIT_DELAYED_WORK(&bond->mii_work, bond_mii_monitor);
> if (bond->params.mode == BOND_MODE_ACTIVEBACKUP)
> @@ -3060,7 +3064,7 @@ static void bond_work_cancel_all(struct bonding *bond)
> {
> cancel_delayed_work_sync(&bond->mii_work);
> cancel_delayed_work_sync(&bond->arp_work);
> - if (bond_is_lb(bond))
> + if (bond_is_lb(bond) && bond->params.tlb_dynamic_lb)
> cancel_delayed_work_sync(&bond->alb_work);
> cancel_delayed_work_sync(&bond->ad_work);
> cancel_delayed_work_sync(&bond->mcast_work);
> @@ -3098,7 +3102,8 @@ static int bond_open(struct net_device *bond_dev)
> */
> if (bond_alb_initialize(bond, (bond->params.mode == BOND_MODE_ALB)))
> return -ENOMEM;
> - queue_delayed_work(bond->wq, &bond->alb_work, 0);
> + if (bond->params.tlb_dynamic_lb)
> + queue_delayed_work(bond->wq, &bond->alb_work, 0);
> }
>
> if (bond->params.miimon) /* link check interval, in milliseconds. */
> @@ -4285,6 +4290,22 @@ static int bond_check_params(struct bond_params *params)
> lp_interval = BOND_ALB_DEFAULT_LP_INTERVAL;
> }
>
> + if (!tlb_dynamic_lb) {
> + if (bond_mode == BOND_MODE_TLB)
> + pr_notice("Dynamic-lb is disabled.\n");
> + else {
Add brackets { } to the if as well (Documentation/CodingStyle: chapter 3)
> + pr_warn("Disabling dynamic-lb is unsupported"
> + " in this mode, force enabling "
> + "dynamic-lb\n");
> + /*
> + * IMPORTANT: Set it to "1" here so that we
> + * dont have to worry about validating mode
> + * before checking value of tlb_dynamic_lb
> + */
> + tlb_dynamic_lb = 1;
> + }
> + }
> +
> /* fill params struct with the proper values */
> params->mode = bond_mode;
> params->xmit_policy = xmit_hashtype;
> @@ -4306,6 +4327,7 @@ static int bond_check_params(struct bond_params *params)
> params->min_links = min_links;
> params->lp_interval = lp_interval;
> params->packets_per_slave = packets_per_slave;
> + params->tlb_dynamic_lb = tlb_dynamic_lb;
> if (packets_per_slave > 0) {
> params->reciprocal_packets_per_slave =
> reciprocal_value(packets_per_slave);
> diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
> index dc3893841752..53a657ea8538 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -70,6 +70,8 @@ static int bond_option_mode_set(struct bonding *bond,
> const struct bond_opt_value *newval);
> static int bond_option_slaves_set(struct bonding *bond,
> const struct bond_opt_value *newval);
> +static int bond_option_tlb_dynamic_lb_set(struct bonding *bond,
> + const struct bond_opt_value *newval);
>
>
> static const struct bond_opt_value bond_mode_tbl[] = {
> @@ -179,6 +181,12 @@ static const struct bond_opt_value bond_lp_interval_tbl[] = {
> { NULL, -1, 0},
> };
>
> +static const struct bond_opt_value bond_tlb_dynamic_lb_tbl[] = {
> + { "off", 0, 0},
> + { "on", 1, BOND_VALFLAG_DEFAULT},
> + { NULL, -1, 0}
> +};
> +
> static const struct bond_option bond_opts[] = {
> [BOND_OPT_MODE] = {
> .id = BOND_OPT_MODE,
> @@ -364,6 +372,14 @@ static const struct bond_option bond_opts[] = {
> .flags = BOND_OPTFLAG_RAWVAL,
> .set = bond_option_slaves_set
> },
> + [BOND_OPT_TLB_DYNAMIC_LB] = {
> + .id = BOND_OPT_TLB_DYNAMIC_LB,
> + .name = "dynamic_lb",
> + .desc = "Enable dynamic flow shuffling",
> + .unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_TLB)),
> + .values = bond_tlb_dynamic_lb_tbl,
> + .set = bond_option_tlb_dynamic_lb_set,
> + },
> { }
> };
>
> @@ -1337,3 +1353,18 @@ err_no_cmd:
> ret = -EPERM;
> goto out;
> }
> +
> +static int bond_option_tlb_dynamic_lb_set(struct bonding *bond,
> + const struct bond_opt_value *newval)
> +{
> + int ret = 0;
> +
> + if (bond->dev->flags & IFF_UP) {
> + pr_err("%s: Cannot change dynamic-lb - interface up.\n",
> + bond->dev->name);
> + ret = -EPERM;
> + } else
> + bond->params.tlb_dynamic_lb = newval->value;
Specially for these cases I added the option flag: BOND_OPTFLAG_IFDOWN
Take a look at how BOND_OPT_LACP_RATE is defined for example.
> +
> + return ret;
> +}
> diff --git a/drivers/net/bonding/bond_options.h b/drivers/net/bonding/bond_options.h
> index 12be9e1bfb0c..c1860f06145a 100644
> --- a/drivers/net/bonding/bond_options.h
> +++ b/drivers/net/bonding/bond_options.h
> @@ -62,6 +62,7 @@ enum {
> BOND_OPT_RESEND_IGMP,
> BOND_OPT_LP_INTERVAL,
> BOND_OPT_SLAVES,
> + BOND_OPT_TLB_DYNAMIC_LB,
> BOND_OPT_LAST
> };
>
> diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
> index 0e8b268da0a0..431892f1a4ce 100644
> --- a/drivers/net/bonding/bond_sysfs.c
> +++ b/drivers/net/bonding/bond_sysfs.c
> @@ -1039,6 +1039,34 @@ static ssize_t bonding_store_lp_interval(struct device *d,
> static DEVICE_ATTR(lp_interval, S_IRUGO | S_IWUSR,
> bonding_show_lp_interval, bonding_store_lp_interval);
>
> +static ssize_t bonding_show_tlb_dynamic_lb(struct device *d,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct bonding *bond = to_bond(d);
> + return sprintf(buf, "%d\n", bond->params.tlb_dynamic_lb);
> +}
> +
> +static ssize_t bonding_store_tlb_dynamic_lb(struct device *d,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t count)
> +{
> + struct bonding *bond = to_bond(d);
> + int ret;
> +
> + ret = bond_opt_tryset_rtnl(bond, BOND_OPT_TLB_DYNAMIC_LB,
> + (char *)buf);
> + if (!ret)
> + ret = count;
> +
> + return ret;
> +}
> +
> +static DEVICE_ATTR(tlb_dynamic_lb, S_IRUGO | S_IWUSR,
> + bonding_show_tlb_dynamic_lb,
> + bonding_store_tlb_dynamic_lb);
> +
> static ssize_t bonding_show_packets_per_slave(struct device *d,
> struct device_attribute *attr,
> char *buf)
> @@ -1099,6 +1127,7 @@ static struct attribute *per_bond_attrs[] = {
> &dev_attr_min_links.attr,
> &dev_attr_lp_interval.attr,
> &dev_attr_packets_per_slave.attr,
> + &dev_attr_tlb_dynamic_lb.attr,
> NULL,
> };
>
> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
> index f91f5dd219d6..c41ac6315c80 100644
> --- a/drivers/net/bonding/bonding.h
> +++ b/drivers/net/bonding/bonding.h
> @@ -174,6 +174,7 @@ struct bond_params {
> int resend_igmp;
> int lp_interval;
> int packets_per_slave;
> + int tlb_dynamic_lb;
> struct reciprocal_value reciprocal_packets_per_slave;
> };
>
>
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