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 <linux-kernel@vger.kernel.org>
  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 <linux-kernel@vger.kernel.org>
  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
  41                 insensitive in the perf tool, the perf tool only looks
  42                 for lower or 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 lower or upper case.
  45
  46                 File contents:
  47
  48                         <term>[=<value>][,<term>[=<value>]]...
  49
  50                 Where <term> is one of the terms listed under
  51                 /sys/bus/event_source/devices/<pmu>/format/ and <value> is
  52                 a number is base-16 format with a '0x' prefix (lowercase only).
  53                 If a <term> is specified alone (without an assigned value), it
  54                 is implied that 0x1 is assigned to that <term>.
  55
  56                 Examples (each of these lines would be in a separate file):
  57
  58                         event=0x2abc
  59                         event=0x423,inv,cmask=0x3
  60                         domain=0x1,offset=0x8,starting_index=0xffff
  61                         domain=0x1,offset=0x8,core=?
  62
  63                 Each of the assignments indicates a value to be assigned to a
  64                 particular set of bits (as defined by the format file
  65                 corresponding to the <term>) in the perf_event structure passed
  66                 to the perf_open syscall.
  67
  68                 In the case of the last example, a value replacing "?" would
  69                 need to be provided by the user selecting the particular event.
  70                 This is referred to as "event parameterization". Event
  71                 parameters have the format 'param=?'.
  72
  73 What: /sys/bus/event_source/devices/<pmu>/events/<event>.unit
  74 Date: 2014/02/24
  75 Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
  76 Description:    Perf event units
  77
  78                 A string specifying the English plural numerical unit that <event>
  79                 (once multiplied by <event>.scale) represents.
  80
  81                 Example:
  82
  83                         Joules
  84
  85 What: /sys/bus/event_source/devices/<pmu>/events/<event>.scale
  86 Date: 2014/02/24
  87 Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
  88 Description:    Perf event scaling factors
  89
  90                 A string representing a floating point value expressed in
  91                 scientific notation to be multiplied by the event count
  92                 received from the kernel to match the unit specified in the
  93                 <event>.unit file.
  94
  95                 Example:
  96
  97                         2.3283064365386962890625e-10
  98
  99                 This is provided to avoid performing floating point arithmetic
 100                 in the kernel.