Documentation/ABI/testing/sysfs-bus-event_source-devices-events

   1 What:           /sys/devices/cpu/events/
   2                 /sys/devices/cpu/events/branch-misses
   3                 /sys/devices/cpu/events/cache-references
   4                 /sys/devices/cpu/events/cache-misses
   5                 /sys/devices/cpu/events/stalled-cycles-frontend
   6                 /sys/devices/cpu/events/branch-instructions
   7                 /sys/devices/cpu/events/stalled-cycles-backend
   8                 /sys/devices/cpu/events/instructions
   9                 /sys/devices/cpu/events/cpu-cycles
  10
  11 Date:           2013/01/08
  12
  13 Contact:        Linux kernel mailing list <[email protected]>
  14
  15 Description:    Generic performance monitoring events
  16
  17                 A collection of performance monitoring events that may be
  18                 supported by many/most CPUs. These events can be monitored
  19                 using the 'perf(1)' tool.
  20
  21                 The contents of each file would look like:
  22
  23                         event=0xNNNN
  24
  25                 where 'N' is a hex digit and the number '0xNNNN' shows the
  26                 "raw code" for the perf event identified by the file's
  27                 "basename".
  28
  29
  30 What: /sys/bus/event_source/devices/<pmu>/events/<event>
  31 Date: 2014/02/24
  32 Contact:        Linux kernel mailing list <[email protected]>
  33 Description:    Per-pmu performance monitoring events specific to the running system
  34
  35                 Each file (except for some of those with a '.' in them, '.unit'
  36                 and '.scale') in the 'events' directory describes a single
  37                 performance monitoring event supported by the <pmu>. The name
  38                 of the file is the name of the event.
  39
  40                 As performance monitoring event names are case insensitive
  41                 in the perf tool, the perf tool only looks for all lower
  42                 case or all upper case event names in sysfs to avoid
  43                 scanning the directory. It is therefore required the
  44                 name of the event here is either completely lower or upper
  45                 case, with no mixed-case characters. Numbers, '.', '_', and
  46                 '-' are also allowed.
  47
  48                 File contents:
  49
  50                         <term>[=<value>][,<term>[=<value>]]...
  51
  52                 Where <term> is one of the terms listed under
  53                 /sys/bus/event_source/devices/<pmu>/format/ and <value> is
  54                 a number is base-16 format with a '0x' prefix (lowercase only).
  55                 If a <term> is specified alone (without an assigned value), it
  56                 is implied that 0x1 is assigned to that <term>.
  57
  58                 Examples (each of these lines would be in a separate file):
  59
  60                         event=0x2abc
  61                         event=0x423,inv,cmask=0x3
  62                         domain=0x1,offset=0x8,starting_index=0xffff
  63                         domain=0x1,offset=0x8,core=?
  64
  65                 Each of the assignments indicates a value to be assigned to a
  66                 particular set of bits (as defined by the format file
  67                 corresponding to the <term>) in the perf_event structure passed
  68                 to the perf_open syscall.
  69
  70                 In the case of the last example, a value replacing "?" would
  71                 need to be provided by the user selecting the particular event.
  72                 This is referred to as "event parameterization". Event
  73                 parameters have the format 'param=?'.
  74
  75 What: /sys/bus/event_source/devices/<pmu>/events/<event>.unit
  76 Date: 2014/02/24
  77 Contact:        Linux kernel mailing list <[email protected]>
  78 Description:    Perf event units
  79
  80                 A string specifying the English plural numerical unit that <event>
  81                 (once multiplied by <event>.scale) represents.
  82
  83                 Example:
  84
  85                         Joules
  86
  87 What: /sys/bus/event_source/devices/<pmu>/events/<event>.scale
  88 Date: 2014/02/24
  89 Contact:        Linux kernel mailing list <[email protected]>
  90 Description:    Perf event scaling factors
  91
  92                 A string representing a floating point value expressed in
  93                 scientific notation to be multiplied by the event count
  94                 received from the kernel to match the unit specified in the
  95                 <event>.unit file.
  96
  97                 Example:
  98
  99                         2.3283064365386962890625e-10
 100
 101                 This is provided to avoid performing floating point arithmetic
 102                 in the kernel.