Bug 455447

Summary: FEAT: RHEL 5.3: (1/2) Increase deep idle state residency on idle platforms using Nehalem class processors
Product: Red Hat Enterprise Linux 5 Reporter: John Villalovos <jvillalo>
Component: kernelAssignee: John Feeney <jfeeney>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: high Docs Contact:
Priority: high    
Version: 5.3CC: andriusb, austin.zhang, bmaly, cward, gcase, jane.lv, jvillalo, keve.a.gabbert, venkatesh.pallipadi, youquan.song
Target Milestone: rcKeywords: FutureFeature
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-01-20 20:02:05 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 428015, 455449, 455516    
Attachments:
Description Flags
Patch for this bug none

Description John Villalovos 2008-07-15 15:26:41 UTC
1. Feature Name: Increase deep idle state residency on idle platforms using
Nehalem class processors

2. Description:
Architectures (mark all that apply)
x 32-bit x86
  64-bit Itanium2
x 64-bit Intel EM64T

Dependencies:
External links:
Priority (H,M,L): H
Target Releases:
Target Release Date:
Drivers or hardware dependency:
Target Kernel:

3. Business Justification:
a. Why is this feature needed?
Big power efficiency improvement.  Have seen savings of approximately 7-8%.
b. What hardware does this enable?
Nehalem CPUs
c. Forecast, volume or high end platform?
Volume
d. Any configuration info?
e. When needed?
f. Are there other dependencies (drivers).

4. Status:
a. Is code accepted upstream? If so, what version or patch?
Will add to bug info

5. Hardware to Red Hat? Red Hat can't integrate/test features without hardware.
Tylersburg-EP systems can be used to test this.

6. Partner management contact, email, phone, chat
keve.a.gabbert

7. Partner technical contact, email, phone, chat
jvillalo

Comment 1 John Villalovos 2008-07-15 15:34:02 UTC
I am going to attach the simpler patch to this bug.

Together the two patches increase the deep idle state residency on an idle
platform and performance/power team folks found >16W savings with these two
patches out of total 220W idle power, which is 7-8%. Of the two patches, first
one is simpler and bigger savings and should be easier to push.


Comment 2 John Villalovos 2008-07-15 15:35:04 UTC
Created attachment 311847 [details]
Patch for this bug

Comment 5 Matthew Garrett 2008-08-06 10:23:20 UTC
Applying this and 455449, I'm not obviously seeing any increase in C3 residency (using powertop as a measuring tool). Is there a recommended way to perform this measurement?

Comment 6 John Villalovos 2008-08-06 11:35:20 UTC
Venki,

Can you answer the question about C3 residency?

Comment 7 Don Zickus 2008-09-13 01:47:44 UTC
in kernel-2.6.18-113.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Comment 10 Chris Ward 2008-11-28 07:14:58 UTC
Partners, this bug should be fixed in the latest RHEL 5.3 Snapshot. We believe that you have some interest in its correct functionality, so we're making a friendly request to send us some testing feedback. 

If you have a chance to test it, please share with us your findings. If you have successfully VERIFIED the fix, please add PartnerVerified to the Bugzilla keywords, along with a description of the results. Thanks!

Comment 11 Song, Youquan 2008-12-02 06:42:04 UTC
Verify on Tylersburg EP, the bug was fixed.

Comment 12 Song, Youquan 2008-12-02 09:29:02 UTC
Verify on Tylersburg EP, the bug was fixed.

Comment 14 errata-xmlrpc 2009-01-20 20:02:05 UTC
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.

http://rhn.redhat.com/errata/RHSA-2009-0225.html