bonding: extend round-robin mode with packets_per_slave
This patch aims to extend round-robin mode with a new option called
packets_per_slave which can have the following values and effects:
0 - choose a random slave
1 (default) - standard round-robin, 1 packet per slave
>1 - round-robin when >1 packets have been transmitted per slave
The allowed values are between 0 and 65535.
This patch also fixes the comment style in bond_xmit_roundrobin().
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a141f40..4dd5ee2 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -79,6 +79,7 @@
#include <net/pkt_sched.h>
#include <linux/rculist.h>
#include <net/flow_keys.h>
+#include <linux/reciprocal_div.h>
#include "bonding.h"
#include "bond_3ad.h"
#include "bond_alb.h"
@@ -111,6 +112,7 @@
static int all_slaves_active;
static struct bond_params bonding_defaults;
static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;
+static int packets_per_slave = 1;
module_param(max_bonds, int, 0);
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
@@ -183,6 +185,10 @@
module_param(resend_igmp, int, 0);
MODULE_PARM_DESC(resend_igmp, "Number of IGMP membership reports to send on "
"link failure");
+module_param(packets_per_slave, int, 0);
+MODULE_PARM_DESC(packets_per_slave, "Packets to send per slave in balance-rr "
+ "mode; 0 for a random slave, 1 packet per "
+ "slave (default), >1 packets per slave.");
/*----------------------------- Global variables ----------------------------*/
@@ -3574,14 +3580,44 @@
kfree_skb(skb);
}
+/**
+ * bond_rr_gen_slave_id - generate slave id based on packets_per_slave
+ * @bond: bonding device to use
+ *
+ * Based on the value of the bonding device's packets_per_slave parameter
+ * this function generates a slave id, which is usually used as the next
+ * slave to transmit through.
+ */
+static u32 bond_rr_gen_slave_id(struct bonding *bond)
+{
+ int packets_per_slave = bond->params.packets_per_slave;
+ u32 slave_id;
+
+ switch (packets_per_slave) {
+ case 0:
+ slave_id = prandom_u32();
+ break;
+ case 1:
+ slave_id = bond->rr_tx_counter;
+ break;
+ default:
+ slave_id = reciprocal_divide(bond->rr_tx_counter,
+ packets_per_slave);
+ break;
+ }
+ bond->rr_tx_counter++;
+
+ return slave_id;
+}
+
static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
struct iphdr *iph = ip_hdr(skb);
struct slave *slave;
+ u32 slave_id;
- /*
- * Start with the curr_active_slave that joined the bond as the
+ /* Start with the curr_active_slave that joined the bond as the
* default for sending IGMP traffic. For failover purposes one
* needs to maintain some consistency for the interface that will
* send the join/membership reports. The curr_active_slave found
@@ -3594,8 +3630,8 @@
else
bond_xmit_slave_id(bond, skb, 0);
} else {
- bond_xmit_slave_id(bond, skb,
- bond->rr_tx_counter++ % bond->slave_cnt);
+ slave_id = bond_rr_gen_slave_id(bond);
+ bond_xmit_slave_id(bond, skb, slave_id % bond->slave_cnt);
}
return NETDEV_TX_OK;
@@ -4099,6 +4135,12 @@
resend_igmp = BOND_DEFAULT_RESEND_IGMP;
}
+ if (packets_per_slave < 0 || packets_per_slave > USHRT_MAX) {
+ pr_warn("Warning: packets_per_slave (%d) should be between 0 and %u resetting to 1\n",
+ packets_per_slave, USHRT_MAX);
+ packets_per_slave = 1;
+ }
+
/* reset values for TLB/ALB */
if ((bond_mode == BOND_MODE_TLB) ||
(bond_mode == BOND_MODE_ALB)) {
@@ -4288,7 +4330,10 @@
params->resend_igmp = resend_igmp;
params->min_links = min_links;
params->lp_interval = BOND_ALB_DEFAULT_LP_INTERVAL;
-
+ if (packets_per_slave > 1)
+ params->packets_per_slave = reciprocal_value(packets_per_slave);
+ else
+ params->packets_per_slave = packets_per_slave;
if (primary) {
strncpy(params->primary, primary, IFNAMSIZ);
params->primary[IFNAMSIZ - 1] = 0;