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trusty (3) libpfm_intel_snbep_unc_cbo.3.gz

NAME

       libpfm_intel_snbep_unc_cbo  -  support  for Intel Sandy Bridge-EP C-Boxuncore PMU

SYNOPSIS

       #include <perfmon/pfmlib.h>PMU name: snbep_unc_cbo[0-7]PMU desc: Intel Sandy Bridge-EP C-Box uncore PMU

DESCRIPTION

       The library supports the Intel Sandy Bridge  C-Box  (coherency  engine)uncore PMU.  This PMU model only exists on Sandy Bridge model 45. Thereis one C-box PMU per physical core. Therefore there are eight identicalC-Box  PMU  instances numbered frmo 0 to 7. On dual-socket systems, thenumber refers to the C-Box PMU on the socket where  the  program  runs.For  instance, if running on CPU8, then snbep_unc_cbo0 refers to the C-Box for physical core 0 on socket 1. Conversely, if  running  on  CPU0,then  the  same  snbep_unc_cbo0 refers to the C-Box for physical core 0but on socket 0.Each C-Box PMU implements 4 generic counters and a filter register usedonly with certain events and umasks.

MODIFIERS

       The  following  modifiers  are  supported  on  Intel Sandy Bridge C-Boxuncore PMU:i      Invert the meaning of the event. The counter will now  count  C-Box  cycles  in  which  the  event  is  not occurring. This is aboolean modifiere      Enable edge detection, i.e., count only when there  is  a  statetransition  from  no  occurrence  of  the  event to at least oneoccurrence. This modifier must  be  combined  with  a  thresholdmodifier  (t)  with  a value greater or equal to one.  This is aboolean modifier.t      Set the threshold value. When  set  to  a  non-zero  value,  thecounter counts the number of C-Box cycles in which the number ofoccurrences of the event is greater or equal to  the  threshold.This is an integer modifier with values in the range [0:255].nf     Node   filter.   Certain   events,   such  as  UNC_C_LLC_LOOKUP,UNC_C_LLC_VICTIMS, provide a NID umask.  Sometimes  the  NID  iscombined  with  other  filtering  capabilities, such as opcodes.The node filter is an 8-bit max bitmask. A node corresponds to aprocessor  socket.  The  legal  values  therefore depdend on theunderlying hardware configuration. For dual-socket systems,  thebitmask has two valid bits [0:1].cf     Core  Filter.  This  is  a  3-bit filter which is used to filterbased on phyiscal core origin of  the  C-Box  request.  Possiblevalues  are  0-7.  If  the  filter  is  not  specified,  then nofiltering takes place.tf     Thread Filter. This is a 1-bit filter which is used to filter C-Box   requests   based   on   logical  processor  (hyper-thread)identification. Possibles values are 0-1. If the filter  is  notspecified, then no filtering takes place.

Opcode filtering

       Certain  events,  such as UNC_C_TOR_INSERTS supports opcode matching onthe C-BOX transaction type.  To  use  this  feature,  first  an  opcodematching umask must be selected, e.g., MISS_OPCODE.  Second, the opcodeto match on must be selected via  a  second  umasks  amongs  the  OPC_*umasks.   For  instance,  UNC_C_TOR_INSERTS:OPCODE:OPC_RFO,  counts thenumber of TOR insertions for RFO transactions.Opcode matching may  be  combined  with  node  filtering  with  certainumasks.  In  general  the  filtering  support is encoded into the umaskname, e.g., NID_OPCODE supports both node  and  opcode  filtering.  Forinstance, UNC_C_TOR_INSERTS:NID_OPCODE:OPC_RFO:nf=1.

AUTHORS

       Stephane Eranian <eranian@gmail>August, 2012                        LIBPFM(3)