1. Feature Overview:
Feature Id: 
a. Name of Feature: [6.1 FEAT] KVM Network Performance: mergeable rx buffers support in vhost-net
b. Feature Description
Enable mergeable rx buffers feature in vhost-net
- improves host to guest throughput/latency for small messages.
- this features is on by default when using userspace virtio
- allows migration between 2 systems with/without vhost.
2. Feature Details:
Sponsor: LTC Networking
Arch Specificity: both
Affects Kernel Modules: Field does not exist
Delivery Mechanism: Backport
Request Type: Kernel - Performance Enhancement from Upstream
d. Upstream Acceptance: Field does not exist
Sponsor Priority P3
f. Severity: high
IBM Confidential: No
Code Contribution: IBM code
g. Component Version Target:
3. Business Case
KVM network performance is a critical requirement for multiple IBM virtualization/cloud based
products and solutions.
4. Primary contact at Red Hat:
5. Primary contacts at Partner:
Project Management Contact:
Michael L. Hohnbaum, firstname.lastname@example.org
David L. Stevens, email@example.com
------- Comment From firstname.lastname@example.org 2010-10-04 10:36 EDT-------
Code Upstream Status: Accepted
Patch(es) available on kernel-2.6.32-94.el6
This enhancement request was evaluated by the full Red Hat Enterprise Linux
team for inclusion in a Red Hat Enterprise Linux minor release. As a
result of this evaluation, Red Hat has tentatively approved inclusion of
this feature in the next Red Hat Enterprise Linux Update minor release.
While it is a goal to include this enhancement in the next minor release
of Red Hat Enterprise Linux, the enhancement is not yet committed for
inclusion in the next minor release pending the next phase of actual
code integration and successful Red Hat and partner testing.
------- Comment From email@example.com 2011-04-06 09:18 EDT-------
This feature has been verified by IBM
Created attachment 490693 [details]
rhel6.1 vhost-net mrg_rxbuf on vs off
Attach the test result of vhost-net mrg_rxbuf=on/off.
From Host -> guest, see guest has high udp consumption packet compared with mrg_rxbu=off,but some performance degradation of
tcp packet with packet size less than 4096, Others looks good.
According comment #12 ,change the bus status to verified.thanks~~
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.