bonding: extend round-robin mode with packets_per_slave

[~andy/linux] / drivers / net / bonding / bond_main.c

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a141f406cb9882ad9b4aaaf1b35b1595b24d9e8a..4dd5ee2a34cc68c4222f4c4115beedaee8b187d2 100644 (file)
--- 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 char *fail_over_mac;
 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_PARM_DESC(all_slaves_active, "Keep all frames received on an interface"
 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 @@ void bond_xmit_slave_id(struct bonding *bond, struct sk_buff *skb, int slave_id)
        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 @@ static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev
                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 @@ static int bond_check_params(struct bond_params *params)
                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 @@ static int bond_check_params(struct bond_params *params)
        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;