Red Hat Bugzilla – Bug 137344
Cannot disable hyperthreading on x86_64 platform
Last modified: 2013-08-05 21:09:31 EDT
Description of problem:
x86_64 doesn't support disabling hyperthreading via the 'noht' kernel
option. This means that the only way to disable hyperthreading via
kernel arguments is with "acpi=off", which is known to break/disable
quite a few things and thus is not a viable alternative
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Boot x86_64 kernel with "noht" parameter
Hyperthreading is still enabled
Hyperthreading is disabled
*** Bug 137101 has been marked as a duplicate of this bug. ***
It should be pretty straightforward to duplicate what we do on the x86
side, modulo some differences in ACPI handling. I see this as
perfectly doable in the U5 timeframe.
So it should be getting fixed in U5?
No, this didn't make U5. I'm testing the patch now that should be slated for U6.
A fix for this problem has just been committed to the RHEL3 U7
patch pool this evening (in kernel version 2.4.21-37.6.EL).
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 the 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.