Red Hat Bugzilla – Bug 202009
powernow-k8: fid trans failed, fid 0xc, curr 0xe
Last modified: 2007-11-30 17:11:40 EST
+++ This bug was initially created as a clone of Bug #191566 +++ Description of problem: Seeing a fair number of: powernow-k8: fid trans failed, fid 0xc, curr 0xe powernow-k8: transition frequency failed # cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 15 model : 43 model name : AMD Athlon(tm)64 X2 Dual Core Processor 4200+ stepping : 1 cpu MHz : 2200.000 cache size : 512 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 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 lm 3dnowext 3dnow pni lahf_lm cmp_legacy bogomips : 5527.18 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 (cpu #1 deleted) Version-Release number of selected component (if applicable): 2.6.16-1.2111_FC5xen0
Seeing the same with FC6test2 and the Xen kernel - spews powernow errors every second or so, with high urgency level that spew all over the console. Not sure if this is a Xen related bug (no powernow and it shouldnt be enabled) or a kernel one.
This seems to be Xen specific. When the Xen dom0 boots up, the powernow-k8_init function is called, which goes around to each CPU to query whether it supports frequency and voltage transition. All of this is read-only, so all of the calls to access the various feature flags of the CPU succeed, and the code thinks that the processor is capable of the transitions. However, later on, when it actually tries to do the transition, the Hypervisor prevents the write to the MSR register, which fails the frequency change, which causes the messages to be continually output. This can be further seen by looking at the messages coming out of both the Hypervisor and the dom0 kernel: (XEN) (file=traps.c, line=1385) Domain attempted WRMSR 00000000c0010041 from 00.powernow-k8: fid trans failed, fid 0x10, curr 0x12 powernow-k8: transition frequency failed
Patch here (haven't tested myself): http://groups.google.com/group/xen-devel-archive/browse_thread/thread/dd1794f10ecf69aa/23a55071d651ee28
Still present in the -200 kernel from rawhide yesterday
Still present in FC6Pre - spewed all over the console, message level regardless and makes Xen unusuable on the afflicted systems.
I was under the impression we were disabling CPU_FREQ for Xen for now until some sanity gets beaten into it on the Xen side.
It was disabled on Oct. 11.