Documentation/trace/histogram-design.rst

76 histogram val and key in the histogram (variables are also included
354 Variables  chapter
357 Variables allow data from one hist trigger to be saved by one hist
370 In terms of the histogram data structures, variables are implemented
569 .vars containing the current value of the variables associated with         | |
703 event_name variables are also set.
736 location.  Note also that the output shows that variables live in the
784 variables and values, they actually live in a separate hist_data
867 variables specified in the wakeup_latency() trace action, and use
873 variables.  In this case, $wakeup_lat is obviously a variable, but
912 the linkages between the field_vars and the variables and references
913 created to implement the field variables.  The details are discussed
1058 also created, which is needed to reference the field variables such as
1073 Once all the variables have been updated, resolve_var_refs() can be
1079 The same process occurs for the field variables associated with the
1097 field variables that then are all passed to the wakeup_latency() trace
1113 are automatically converted into field variables for this purpose::
1163 val fields section, but that the new field variables are not there -
1164 although the field variables are variables, they're held separately in
1165 the hist_data's field_vars[] array.  Although the field variables and
1166 the normal variables are located in separate places, you can see that
1167 the actual variable locations for those variables in the
1169 wakeup_lat takes the var.idx = 0 slot, while the field variables for
1172 references corresponding to those variables in the variable reference
1181 Finally, the action tracking variables section just shows the system
1271   field variables:
1301   action tracking variables (for onmax()/onchange()/onmatch()):
1319 variables or are converted into variables (via field variables), and
1357 variables.  This information is contained in the
1389 both the onmax() handler and save() action, variables will be created,
1440 First, the action tracking variables section now shows the
1442 variables and references used to track, in this case, the running
1451 Finally, in the new 'save action variables' section, we can see that
1452 the 4 params to the save() function have resulted in 4 field variables
1454 fields when the max is hit.  These variables are kept in a separate
1523   action tracking variables (for onmax()/onchange()/onmatch()):
1545   save action variables (save() params):
1614 tend to create even more confusion.  Those are field variables on other
1618 Test of field variables on other histograms
1754 the details of which are in the field variables section::
1843   field variables:
1859   action tracking variables (for onmax()/onchange()/onmatch()):
2088   field variables:
2104   action tracking variables (for onmax()/onchange()/onmatch()):