Red Hat Bugzilla – Bug 599332
e1000 and e1000e driver behaviour differences [rhel-5.5.z]
Last modified: 2015-05-04 21:20:10 EDT
This bug has been copied from bug #586416 and has been proposed
to be backported to 5.5 z-stream (EUS).
*** Bug 599331 has been marked as a duplicate of this bug. ***
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.
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
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.