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:
I took the earlier BZ for this so I'll do this one too ... P.
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.
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.
So, as reported, the 32-bit and 64-bit xen kernels do not output the ida flag. Patch coming ... P.
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
Created attachment 362685 [details] RHEL5 fix for this issue
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.
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.
The flag is now present. I tried the -182 Xen kernel and can see the 'ida' cpu flag.
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
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
* 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
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