pmgetderivedcontrol(3) — Linux manual page


PMDERIVEDCONTROL(3)     Library Functions Manual     PMDERIVEDCONTROL(3)

NAME         top

       pmGetDerivedControl, pmSetDerivedControl  - get and set controls
       for derived metrics

C SYNOPSIS         top

       #include <pcp/pmapi.h>

       int pmGetDerivedControl(int what, int *valuep);
       int pmSetDerivedControl(int what, int value);

       cc ... -lpcp

DESCRIPTION         top

       These routines may be used to influence the behaviour of the
       derived metric services that are activated for global derived
       metrics using pmRegisterDerived(3), pmRegisterDerivedMetric(3)
       and pmLoadDerivedConfig(3), or per-context derived metrics using
       pmAddDerived(3) and pmAddDerivedDerived(3).

       The what argument selects a control, the value argument provides
       a value for pmSetDerivedControl and the valuep argument is used
       to return the value for pmGetDerivedControl.

       The what argument has one of the following values:

              The maximum number of global derived metrics that may be
              defined.  The value -1 indicates no limit.

              The maximum number of per-context derived metrics that may
              be defined.  The value -1 indicates no limit.

              Debug diagnostics during parsing of derived metric
              expression.  The value 1 enables the diagnostics, the
              value 0 disables them.

              Debug diagnostics for semantic checks during the binding
              of metrics in the derived metric expression to the
              available metrics in a new PMAPI context.  The value 1
              enables the diagnostics, the value 0 disables them.

              Debug diagnostics when derived metrics are used in PMAPI
              operations like pmFetch(3), pmGetChildren(3),
              pmGetChildrenStatus(3), pmLookupDesc(3), pmLookupName(3),
              pmNameAll(3), pmNameID(3) and pmTraversePMNS(3).

RETURN VALUES         top

       Both routines return 0 on success, else a value less than 0 that
       can be decoded using pmErrStr(3).

SEE ALSO         top

       PCPIntro(1), pmAddDerived(3), pmAddDerivedMetric(3), PMAPI(3),
       pmErrStr(3), pmLoadDerivedConfig(3), pmRegisterDerived(3),
       pmRegisterDerivedMetric(3) and PMNS(5).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨⟩ on 2020-12-18.
       (At that time, the date of the most recent commit that was found
       in the repository was 2020-12-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Performance Co-Pilot                                 PMDERIVEDCONTROL(3)