Amithash Prasad wrote: > Oh, now I see your confusion. > > The cpufreq system is organized as drivers and governors which are two > separate entities with separate jobs: > cpufreq_drivers: example, acpi_cpufreq (Intel), powernow_k8 (AMD) etc. > These are responsible for the mechanism of changing the clock speed / voltage. > > cpufreq_governors: ondemand,conservative,performance etc > These are responsible for the policy of how and when should the > clockspeed change. > > You need both The "cpufreq driver" and "cpufreq governor" in order for > cpufreq to work. If either one is missing, then the capability is > lost. > > The governor/driver make the cpufreq subdirectory available so you can > use/configure it. OK, thanks, that helps. > Let me recommend <kernel Source>/Documentation/cpu-freq/* they will > explain things well. Well, I have read that, but I'll do that again, with your added insights. > 2009/6/12 Randy Dunlap <randy.dunlap@xxxxxxxxxx>: >> Amithash Prasad wrote: >>> Can you try by configuring the kernel to have the powernow_k8 cpufreq >>> driver as a module, and insert it later on? >> Sure, done. And I can see a cpufreq/ sub-directory in each >> /sys/devices/system/cpu/cpuX/ now. Thanks. >> >> but why? Do the other governors not use a cpufreq/ sub-directory? >> >> >> However: I cannot see any significant power vs. performance benefits >> on my server system by using cpufreq. Can anyone suggest some >> config or /sys settings that might show such benefits? >> >> Thanks. >> >>> I have had a few issues when the drivers are compiled into the kernel. >>> >>> On Thu, Jun 11, 2009 at 10:25 AM, Randy Dunlap<randy.dunlap@xxxxxxxxxx> wrote: >>>> Hi, >>>> >>>> I'm trying to test some cpufreq governors. >>>> The target test system is an HP BladeCenter ProLiant BL685c G1. >>>> >>>> /proc/cpuinfo is at end of this email. >>>> >>>> I don't see a cpufreq/ directory in /sys/devices/system/cpu/cpuX/ at all. >>>> >>>> I have loaded 3 cpufreq driver modules: conservative, ondemand, and powersave; >>>> and the performance cpufreq driver is built into the kernel image and is >>>> the default. >>>> >>>> >>>> Am I doing something wrong? or does this CPU not work with cpufreq? >>>> >>>> Thanks, >>>> -- >>>> ~Randy >>>> LPC 2009, Sept. 23-25, Portland, Oregon >>>> http://linuxplumbersconf.org/2009/ >>>> >>>> >>>> /proc/cpuinfo: >>>> >>>> processor : 0 >>>> vendor_id : AuthenticAMD >>>> cpu family : 15 >>>> model : 65 >>>> model name : Dual-Core AMD Opteron(tm) Processor 8218 >>>> stepping : 2 >>>> cpu MHz : 2612.360 >>>> cache size : 1024 KB >>>> physical id : 0 >>>> siblings : 2 >>>> core id : 0 >>>> cpu cores : 2 >>>> apicid : 0 >>>> initial apicid : 0 >>>> fpu : yes >>>> fpu_exception : yes >>>> cpuid level : 1 >>>> wp : yes >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov >>>> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno >>>> wext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy >>>> bogomips : 5224.72 >>>> TLB size : 1024 4K pages >>>> clflush size : 64 >>>> cache_alignment : 64 >>>> address sizes : 40 bits physical, 48 bits virtual >>>> power management: ts fid vid ttp tm stc >>>> >>>> processor : 1 >>>> vendor_id : AuthenticAMD >>>> cpu family : 15 >>>> model : 65 >>>> model name : Dual-Core AMD Opteron(tm) Processor 8218 >>>> stepping : 2 >>>> cpu MHz : 2612.360 >>>> cache size : 1024 KB >>>> physical id : 1 >>>> siblings : 2 >>>> core id : 0 >>>> cpu cores : 2 >>>> apicid : 2 >>>> initial apicid : 2 >>>> fpu : yes >>>> fpu_exception : yes >>>> cpuid level : 1 >>>> wp : yes >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov >>>> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno >>>> wext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy >>>> bogomips : 5223.81 >>>> TLB size : 1024 4K pages >>>> clflush size : 64 >>>> cache_alignment : 64 >>>> address sizes : 40 bits physical, 48 bits virtual >>>> power management: ts fid vid ttp tm stc >>>> >>>> processor : 2 >>>> vendor_id : AuthenticAMD >>>> cpu family : 15 >>>> model : 65 >>>> model name : Dual-Core AMD Opteron(tm) Processor 8218 >>>> stepping : 2 >>>> cpu MHz : 2612.360 >>>> cache size : 1024 KB >>>> physical id : 0 >>>> siblings : 2 >>>> core id : 1 >>>> cpu cores : 2 >>>> apicid : 1 >>>> initial apicid : 1 >>>> fpu : yes >>>> fpu_exception : yes >>>> cpuid level : 1 >>>> wp : yes >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov >>>> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno >>>> wext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy >>>> bogomips : 5223.80 >>>> TLB size : 1024 4K pages >>>> clflush size : 64 >>>> cache_alignment : 64 >>>> address sizes : 40 bits physical, 48 bits virtual >>>> power management: ts fid vid ttp tm stc >>>> >>>> processor : 3 >>>> vendor_id : AuthenticAMD >>>> cpu family : 15 >>>> model : 65 >>>> model name : Dual-Core AMD Opteron(tm) Processor 8218 >>>> stepping : 2 >>>> cpu MHz : 2612.360 >>>> cache size : 1024 KB >>>> physical id : 1 >>>> siblings : 2 >>>> core id : 1 >>>> cpu cores : 2 >>>> apicid : 3 >>>> initial apicid : 3 >>>> fpu : yes >>>> fpu_exception : yes >>>> cpuid level : 1 >>>> wp : yes >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov >>>> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno >>>> wext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy >>>> bogomips : 5223.80 >>>> TLB size : 1024 4K pages >>>> clflush size : 64 >>>> cache_alignment : 64 >>>> address sizes : 40 bits physical, 48 bits virtual >>>> power management: ts fid vid ttp tm stc >>>> ===== -- ~Randy LPC 2009, Sept. 23-25, Portland, Oregon http://linuxplumbersconf.org/2009/ -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
