Red Hat Bugzilla – Bug 463551
[LTC 6.0 FEAT] 201064:Standby cpu activation/deactivation.
Last modified: 2010-09-29 04:51:28 EDT
Emily J. Ratliff <firstname.lastname@example.org> - 2008-09-16 17:56 EDT
1. Feature Overview:
Feature Id: 
a. Name of Feature: Standby cpu activation/deactivation.
b. Feature Description
Make use of the 'Configure CPU' and 'Deconfigure CPU' SCLP commands to switch cpus between the
standby and the operating state when they are enabled / disabled with the cpu online attribute. This
allows Linux to make use of standby cpus which are not visible until they are activated.
2. Feature Details:
Arch Specificity: Purely Arch Specific Code
Affects Core Kernel: Yes
Affects Kernel Modules: Yes
Delivery Mechanism: Direct from community
Request Type: Kernel - Enhancement from IBM
d. Upstream Acceptance: Accepted
Sponsor Priority 1
f. Severity: High
IBM Confidential: no
Code Contribution: IBM code
g. Component Version Target: 2.6.25
3. Business Case
Improve manageability of Linux Systems. Allow for on-demand adjustment of CPU capacity.
4. Primary contact at Red Hat:
5. Primary contacts at Partner:
Project Management Contact:
Hans-Georg Markgraf, email@example.com, Boeblingen 49-7031-16-3978
Gonzalo Muelas Serrano, firstname.lastname@example.org
Thomas Schwarz, email@example.com
RHEL 6 will include a kernel newer than 2.6.25, so this should not be a problem.
The feature requested has already been accepted into the upstream code base
planned for the next major release of Red Hat Enterprise Linux.
When the next milestone release of Red Hat Enterprise Linux 6 is available,
please verify that the feature requested is present and functioning as
Code is included in the rhel6 kernel via upstream. Marked as
CLOSED/CURRENTRELEASE by Hans-Joachim Picht <firstname.lastname@example.org>
------- Comment From email@example.com 2010-07-06 16:05 EDT-------
Reported the following bug to be fixed for this feature request
LTC 65629 - RIT1082533- kernel: CPU hotplug vs migration thread
that causes a system hang and should be fixed
------- Comment From firstname.lastname@example.org 2010-08-30 09:50 EDT-------
This is verified on R6 snapshots
-> set to verified Thx
Both reported bugs are also verified ok and closed
66348 - RIT1219973- [RHEL6.0] system hangs while making standby cpu online/offline in a loop
65629 - RIT1082533- kernel: CPU hotplug vs migration thread
------- Comment From email@example.com 2010-09-29 04:45 EDT-------
This feature is verified ok.