Cannot allocate system-mode PMC with spec. "instructions"

[Jeremie Le Hen]

Hi list, Joseph,

__ Please Cc: me when replying, as I'm not subscribed. __

I've tried to sample my system while performing a big copy between UFS
to ZFS using the following command:
  % # pmcstat -v -S instructions -O $PWD/sample.out
  % pmcstat: ERROR: Cannot allocate system-mode pmc with specification "instructions": Invalid argument

Oddly, other generic events lead to different errors:
  % obiwan:~/tmp# pmcstat -vv -S cycles -O $PWD/sample.out
  % pmcstat: ERROR: Cannot allocate system-mode pmc with specification "cycles": Operation not supported

But for instance the following works:
  % obiwan:~/tmp# pmcstat -vv -S branches -O $PWD/sample.out 
  % ^Cobiwan:~/tmp# pmcstat -R sample.out -g
  % CONVERSION STATISTICS:
  %  #samples/total                           3110
  %  #samples/unclaimed                       87
  %  #callchain/dubious-frames                87


Additional useful informations are:

  % CPU: Intel(R) Core(TM)2 CPU          6320  @ 1.86GHz (1869.87-MHz 686-class CPU)
  %   Origin = "GenuineIntel"  Id = 0x6f6  Stepping = 6
  %   Features=0xbfebfbff<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,HTT,TM,PBE>
  %   Features2=0xe3bd<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM>
  %   AMD Features=0x20000000<LM>
  %   AMD Features2=0x1<LAHF>
  %   TSC: P-state invariant

  % hwpmc: TSC/1/64/0x20<REA> IAP/2/40/0x3ff<INT,USR,SYS,EDG,THR,REA,WRI,INV,QUA,PRC> IAF/0/0/0x61<INT,REA,WRI>


Regards,
-- 
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >