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Bug 522846

Summary: Nehalem Turbo Boost "ida" flag not present in Xen kernel's /proc/cpuinfo output
Product: Red Hat Enterprise Linux 5 Reporter: Gary Case <gcase>
Component: kernelAssignee: Prarit Bhargava <prarit>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.4CC: aldreygalindo, cward, dzickus, james.brown, pbenas
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-03-30 07:38:54 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: 526775, 533192    
Attachments:
Description Flags
RHEL5 fix for this issue none

Description Gary Case 2009-09-11 18:44:19 UTC
Description of problem:
The "ida" flag, which indicates the presence of the Turbo Boost feature, is not seen in the cpuflags section of /proc/cpuinfo on Xen kernels.

Version-Release number of selected component (if applicable):
kernel-2.6.18-164 xen kernel

How reproducible:
Every time

Steps to Reproduce:
1. Boot system using Xen kernel
2. Check /proc/cpuinfo cpuflags section
3. No 'ida' present
  
Actual results:
No 'ida' displayed.

Expected results:
Flag 'ida' displayed when running on a Nehalem system.

Additional info:

Comment 1 Prarit Bhargava 2009-09-22 15:55:48 UTC
I took the earlier BZ for this so I'll do this one too ...

P.

Comment 2 Gary Case 2009-09-25 01:03:30 UTC
Thanks, Prarit. We need a way to know if Turbo Boost is active, because it messes with our certification results. The time it takes for us to calculate test workloads is less than can be accounted for by the displayed clock speed. If we had the 'ida' flag, we would know to expect discrepancies due to the automatic overclocking that occurs with Turbo Boost.

Comment 3 Prarit Bhargava 2009-09-25 13:33:24 UTC
FWIW: it is present in bare-metal

[root@intel-s3e36-01 kernel]# uname -a
Linux intel-s3e36-01.lab.bos.redhat.com 2.6.18-164.el5 #1 SMP Tue Aug 18 15:51:48 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux

flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm

Trying xen kernel next...

P.

Comment 4 Prarit Bhargava 2009-09-25 15:08:27 UTC
So, as reported, the 32-bit and 64-bit xen kernels do not output the ida flag.

Patch coming ...

P.

Comment 5 Prarit Bhargava 2009-09-25 15:09:49 UTC
2.6.18-166.el5

flags           : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm

2.6.18-166.el5 + patch

flags           : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc ida pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm

Comment 6 Prarit Bhargava 2009-09-25 15:13:21 UTC
Created attachment 362685 [details]
RHEL5 fix for this issue

Comment 7 RHEL Program Management 2009-09-25 17:38:09 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 8 Don Zickus 2009-10-06 19:39:20 UTC
in kernel-2.6.18-168.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Please do NOT transition this bugzilla state to VERIFIED until our QE team
has sent specific instructions indicating when to do so.  However feel free
to provide a comment indicating that this fix has been verified.

Comment 10 Gary Case 2010-01-07 17:06:14 UTC
The flag is now present. I tried the -182 Xen kernel and can see the 'ida' cpu flag.

Comment 12 Petr Beňas 2010-03-19 13:13:55 UTC
bug state changed from ON_QA to VERIFIED 
[root@ibm-hs22-03 ~]# uname -r 
2.6.18-167.el5xen 
[root@ibm-hs22-03 ~]# cat /proc/cpuinfo | grep flags 
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm 

[root@ibm-hs22-03 ~]# uname -r 
2.6.18-194.el5 
[root@ibm-hs22-03 ~]# cat /proc/cpuinfo | grep flags | grep ida 
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 sse4_2 popcnt lahf_lm

Comment 14 errata-xmlrpc 2010-03-30 07:38:54 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-2010-0178.html

Comment 15 Aldrey Galindo 2010-09-16 13:37:57 UTC
* Hardware
 Product Name: PowerEdge T310

[root@srv ~]# uname -r 
2.6.18-194.11.3.el5
[root@srv ~]# grep "vmx" /proc/cpuinfo
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr sse4_1 sse4_2 popcnt lahf_lm

[root@srv ~]# uname -r 
2.6.18-194.11.3.el5xen
[root@srv ~]# grep "vmx" /proc/cpuinfo
flags		: fpu tsc msr pae cx8 apic mtrr cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc ida pni est ssse3 cx16 sse4_1 sse4_2 popcnt lahf_lm

Comment 16 Gary Case 2010-09-16 13:49:17 UTC
Aldrey,

The missing VMX flag in the Xen kernel is being discussed in separate bugzillas:

RHEL5.6
https://bugzilla.redhat.com/show_bug.cgi?id=570091

RHEL5.5.z
https://bugzilla.redhat.com/show_bug.cgi?id=624365

-Gary