diff options
| author | Mahesh Bandewar <maheshb@google.com> | 2014-04-22 16:30:22 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-04-24 13:04:34 -0400 |
| commit | e9f0fb88493570200b8dc1cc02d3e676412d25bc (patch) | |
| tree | edd781d8c00772c53e0736a95cf26f0ef2e620dc /Documentation/networking | |
| parent | f05b42eaa22cd7c6736d31316e6046c5127f8721 (diff) | |
bonding: Add tlb_dynamic_lb parameter for tlb mode
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 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> -- -r81920,81920
Transactions per second:
Before change: 1,367.11
After change: 1,470.65
Change-Id: Ie3f75c77282cf602e83a6e833c6eb164e72a0990
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/bonding.txt | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index a97c567f24e..9c723ecd002 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -585,13 +585,19 @@ mode balance-tlb or 5 Adaptive transmit load balancing: channel bonding that - does not require any special switch support. The - outgoing traffic is distributed according to the - current load (computed relative to the speed) on each - slave. Incoming traffic is received by the current - slave. If the receiving slave fails, another slave - takes over the MAC address of the failed receiving - slave. + does not require any special switch support. + + In tlb_dynamic_lb=1 mode; the outgoing traffic is + distributed according to the current load (computed + relative to the speed) on each slave. + + In tlb_dynamic_lb=0 mode; the load balancing based on + current load is disabled and the load is distributed + only using the hash distribution. + + Incoming traffic is received by the current slave. + If the receiving slave fails, another slave takes over + the MAC address of the failed receiving slave. Prerequisite: @@ -736,6 +742,28 @@ primary_reselect This option was added for bonding version 3.6.0. +tlb_dynamic_lb + + Specifies if dynamic shuffling of flows is enabled in tlb + mode. The value has no effect on any other modes. + + The default behavior of tlb mode is to shuffle active flows across + slaves based on the load in that interval. This gives nice lb + characteristics but can cause packet reordering. If re-ordering is + a concern use this variable to disable flow shuffling and rely on + load balancing provided solely by the hash distribution. + xmit-hash-policy can be used to select the appropriate hashing for + the setup. + + The sysfs entry can be used to change the setting per bond device + and the initial value is derived from the module parameter. The + sysfs entry is allowed to be changed only if the bond device is + down. + + The default value is "1" that enables flow shuffling while value "0" + disables it. This option was added in bonding driver 3.7.1 + + updelay Specifies the time, in milliseconds, to wait before enabling a |