Bug 599331

Summary: e1000 and e1000e driver behaviour differences [rhel-5.5.z]
Product: Red Hat Enterprise Linux 5 Reporter: RHEL Product and Program Management <pm-rhel>
Component: kernelAssignee: Red Hat Kernel Manager <kernel-mgr>
Status: CLOSED DUPLICATE QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 5.3CC: dhoward, dnelson, esammons, gcase, jesse.brandeburg, jpirko, jwest, jwilson, rpacheco
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
The e1000 and e1000e drivers for Intel PRO/1000 network devices were updated with an enhanced algorithm for adaptive interrupt modulation in the Red Hat Enterprise Linux 5.1 release. When InterruptThrottleRate was set to "1" (thus enabling the new adaptive mode), certain traffic patterns could have caused high CPU usage. This update provides a way to set InterruptThrottleRate to "4", which switches the mode back to the simpler and non-adaptive algorithm. Doing so may decrease CPU usage by the e1000 and e1000e drivers depending on traffic patterns. Note: you can change the InterruptThrottleRate setting using the ethtool utility by running the following command: ethtool -C ethX rx-usecs 4
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-06-03 17:08:18 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 586416    
Bug Blocks:    

Description RHEL Product and Program Management 2010-06-03 07:03:11 UTC
This bug has been copied from bug #586416 and has been proposed
to be backported to 5.5 z-stream (EUS).

Comment 1 Don Howard 2010-06-03 17:08:18 UTC

*** This bug has been marked as a duplicate of bug 599332 ***

Comment 3 Douglas Silas 2010-06-28 20:30:26 UTC
Technical note added. If any revisions are required, please edit the "Technical Notes" field
accordingly. All revisions will be proofread by the Engineering Content Services team.

New Contents:
The e1000 and e1000e drivers for Intel PRO/1000 network devices were updated with an enhanced algorithm for adaptive interrupt modulation in the Red Hat Enterprise Linux 5.1 release. When InterruptThrottleRate was set to "1" (thus enabling the new adaptive mode), certain traffic patterns could have caused high CPU usage. This update provides a way to set InterruptThrottleRate to "4", which switches the mode back to the simpler and non-adaptive algorithm. Doing so may decrease CPU usage by the e1000 and e1000e drivers depending on traffic patterns.

Note: you can change the InterruptThrottleRate setting using the ethtool utility by running the following command:

    ethtool -C ethX rx-usecs 4