Bug 683876

Summary: Possible network throughput regression
Product: Red Hat Enterprise Linux 6 Reporter: Adam Okuliar <aokuliar>
Component: kernelAssignee: Andy Gospodarek <agospoda>
Status: CLOSED NOTABUG QA Contact: Network QE <network-qe>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 6.1CC: arozansk, kzhang, lwang, peterm
Target Milestone: rcKeywords: Regression
Target Release: 6.2   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-06-21 16:57:55 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Attachments:
Description Flags
script for system preparing none

Description Adam Okuliar 2011-03-10 14:58:25 UTC 
Created attachment 483475 [details]
script for system preparing

Description of problem:
Network throughput regression on Intel 82599EB 10-Gigabit NIC

Version-Release number of selected component (if applicable):
Linux hp-dl380g7-01.lab.eng.brq.redhat.com 2.6.32-119.el6.x86_64 #1 SMP Tue Mar 1 17:54:42 EST 2011 x86_64 x86_64 x86_64 GNU/Linux


How reproducible:
100%

Steps to Reproduce:
1.provision hp-dl380g7-01.lab.eng.brq.redhat.com and hp-dl385g7-01.lab.eng.brq.redhat.com with rhel6.1

2.run prepare_sys.py (attached) on both systems.

3. run netperf benchmark 
https://brewweb.devel.redhat.com/buildinfo?buildID=135954
netperf -H 127.0.0.1 -- -m 1000
(-m 1000 means, that we will be sending 1000byte long messages)

4. run 24 parralel instances of netperf benchmark
for i in `seq 1 24`; do netperf -H 127.0.0.1 -P0 -- -m 100 | awk '{print $5}' & done
and sum throughput.



Actual results:

With single instance sending 1000byte long messages we have only ~79% of rhel6.0 performance. Please see:
http://download.englab.brq.redhat.com/perf-results//netperf/RHEL61-20110304/#t4_172-16-29-10_to_172-16-29-20

With 24 concurrent instances we have only 75% of rhel6.0. Please see more detailed results.
http://download.englab.brq.redhat.com/perf-results//netperf/RHEL61-20110304/#t4_multi_172-16-29-10_to_172-16-29-20

Expected results:
Performance improved to 6.0 levels

Additional info:
I can provide access to those systems and also help with configuration
Comment 6 Andy Gospodarek 2011-06-21 16:57:55 UTC 
This does not exercise the network devices at all as you are connecting to an IP address local to the system (127.0.0.1 in this case).

Please reopen if you can find benchmarks that indicate that RHEL6.1 has lower stack performance than RHEL6.0 and assign this to someone on Linda Wang's team as her team handles issues that are not networking hardware specific.