6 thoughts on - CentOS 6 / Intel CPU Support

• I found this

  linux-2.6.32-696.1.1.el6/arch/x86/kernel/setup.c

  796 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
  797 ((boot_cpu_data.x86 == 6))) {
  798 switch (boot_cpu_data.x86_model) {
  799 case 94: /* Skylake-S */
  800 case 86: /* Broadwell-DE SoC */
  801 case 85: /* Purley */
  802 case 79: /* Broadwell-EP and EX */
  803 case 78: /* Skylake-Y */
  804 case 77: /* Atom Avoton */
  805 case 71: /* Broadwell-H */
  806 case 70: /* Crystal Well */
  807 break;
  808 default:
  809 if (boot_cpu_data.x86_model > 63) {
  810 printk(KERN_CRIT
  811 “Detected CPU family %d model %d\n”,
  812 boot_cpu_data.x86,
  813 boot_cpu_data.x86_model);
  814 mark_hardware_unsupported(“Intel CPU model”);
  815 }
  816 break;
  817 }
  818 }

  not sure if “case 94: /* Skylake-S */” means support for Intel Core i7-6700 Quad-Core Skylake …

• for the record:

  model 94 seems to be supported since EL6.7.

  A quick install could be booted without issues.

  # cat /proc/cpuinfo | head -26 ; uname -a processor : 0
  vendor_id : GenuineIntel cpu family : 6
  model : 94
  model name : Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz stepping : 3
  microcode : 85
  cpu MHz : 3408.025
  cache size : 8192 KB
  physical id : 0
  siblings : 8
  core id : 0
  cpu cores : 4
  apicid : 0
  initial apicid : 0
  fpu : yes fpu_exception : yes cpuid level : 22
  wp : yes 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 pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch ida arat epb xsaveopt pln pts dtherm hwp hwp_noitfy hwp_act_window hwp_epp tpr_shadow vnmi flexpriority ept vpid fsgsbase bmi1 hle avx2 smep bmi2 erms invpcid rtm rdseed adx bogomips : 6816.05
  clflush size : 64
  cache_alignment : 64
  address sizes : 39 bits physical, 48 bits virtual power management:

  Linux srv-s01.ccds.de 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Apr 11 17:13:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• Here’s mine. Interesting differences:

  # cat /proc/cpuinfo | head -26; uname -a processor : 0
  vendor_id : GenuineIntel cpu family : 6
  model : 94
  model name : Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz stepping : 3
  microcode : 0x9e cpu MHz : 899.945
  cache size : 6144 KB
  physical id : 0
  siblings : 8
  core id : 0
  cpu cores : 4
  apicid : 0
  initial apicid : 0
  fpu : yes fpu_exception : yes cpuid level : 22
  wp : yes 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 pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64
  monitor ds_cpl vmx est tm2 ssse3 fma cx16 xtpr pdcm pcid sse4_1 sse4_2
  x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch ida arat epb pln pts dtherm hwp hwp_noitfy hwp_act_window hwp_epp intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1
  bogomips : 5184.00
  clflush size : 64
  cache_alignment : 64
  address sizes : 39 bits physical, 48 bits virtual power management:

  Linux null.example.com 3.10.0-514.16.1.el7.x86_64 #1 SMP Wed Apr 12
  15:04:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• If you disable Intel Speedstep in the BIOS it should lock the CPU to its fastest speed, but you lose power saving during idle.

• Could you possibly also find that you’re more restricted in your use of TurboBoost in that state (if indeed it works properly without speedstep), and so find it runs slower for some workloads?

  jh

• I’m using corei3 but centos7 is not support at install time