bonding: update bonding.txt for Layer2 hash factors

Document the Layer 2 hash factors with packet type ID field.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: David S. Miller <davem@davemloft.net>
CC: Pan Jiafei <Jiafei.Pan@freescale.com>

Signed-off-by: Jianhua Xie <jianhua.xie@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 15 deletions

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 9c723ecd0025..eeb5b2e97bed 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -542,10 +542,10 @@ mode
 
                 XOR policy: Transmit based on the selected transmit
                 hash policy.  The default policy is a simple [(source
-                MAC address XOR'd with destination MAC address) modulo
-                slave count].  Alternate transmit policies may be
-                selected via the xmit_hash_policy option, described
-                below.
+                MAC address XOR'd with destination MAC address XOR
+                packet type ID) modulo slave count].  Alternate transmit
+                policies may be selected via the xmit_hash_policy option,
+                described below.
 
                 This mode provides load balancing and fault tolerance.
 
@@ -801,10 +801,11 @@ xmit_hash_policy
 
         layer2
 
-                Uses XOR of hardware MAC addresses to generate the
-                hash.  The formula is
+                Uses XOR of hardware MAC addresses and packet type ID
+                field to generate the hash. The formula is
 
-                (source MAC XOR destination MAC) modulo slave count
+                hash = source MAC XOR destination MAC XOR packet type ID
+                slave number = hash modulo slave count
 
                 This algorithm will place all traffic to a particular
                 network peer on the same slave.
@@ -819,7 +820,7 @@ xmit_hash_policy
                 Uses XOR of hardware MAC addresses and IP addresses to
                 generate the hash.  The formula is
 
-                hash = source MAC XOR destination MAC
+                hash = source MAC XOR destination MAC XOR packet type ID
                 hash = hash XOR source IP XOR destination IP
                 hash = hash XOR (hash RSHIFT 16)
                 hash = hash XOR (hash RSHIFT 8)
@@ -2301,13 +2302,13 @@ broadcast: Like active-backup, there is not much advantage to this
         bandwidth.  
 
         Additionally, the linux bonding 802.3ad implementation
-        distributes traffic by peer (using an XOR of MAC addresses),
-        so in a "gatewayed" configuration, all outgoing traffic will
-        generally use the same device.  Incoming traffic may also end
-        up on a single device, but that is dependent upon the
-        balancing policy of the peer's 8023.ad implementation.  In a
-        "local" configuration, traffic will be distributed across the
-        devices in the bond.
+        distributes traffic by peer (using an XOR of MAC addresses
+        and packet type ID), so in a "gatewayed" configuration, all
+        outgoing traffic will generally use the same device.  Incoming
+        traffic may also end up on a single device, but that is
+        dependent upon the balancing policy of the peer's 8023.ad
+        implementation.  In a "local" configuration, traffic will be
+        distributed across the devices in the bond.
 
         Finally, the 802.3ad mode mandates the use of the MII monitor,
         therefore, the ARP monitor is not available in this mode.