__pmequivindom(3) — Linux manual page

PMEQUIVINDOM(3)         Library Functions Manual         PMEQUIVINDOM(3)

NAME

       __pmEquivInDom - check if two instance domains are equivalent

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/libpcp.h>

       int __pmEquivInDom(pmInDom a, pmInDom b)

       cc ... -lpcp

CAVEAT

       This documentation is intended for internal Performance Co-Pilot
       (PCP) developer use.

       These interfaces are not part of the PCP APIs that are guaranteed
       to remain fixed across releases, and at some point in the future
       they may not work or may provide different semantics.

DESCRIPTION

       Within the Performance Co-Pilot (PCP) each instance domain is
       assigned a unique Instance Domain Identifier (pmInDom).
       Internally a pmInDom is constructed from 2 fields: the domain
       number (of the associated Performance Metrics Domain Agent, or
       PMDA) and the serial number (assigned by the PMDA).

       In some unusual circumstances different PMDAs may support
       independent Instance Domains that are semantically equivalent,
       e.g. per CPU or per process identifier.  __pmEquivInDom provides
       a mechanism to determine if Instance Domain a is equivalent to
       Instance Domain b.

       The ``equivalence'' of Instance Domains is defined by an external
       configuration file, identified by the environment variable
       $PCP_INDOM_CONFIG or $PCP_ETC_DIR/pcp/indom.config by default.
       The format for the configuration file is defined in the
       CONFIGURATION FILE section below.

       If $PCP_INDOM_CONFIG is an empty string, no equivalence mapping
       is loaded.

CONFIGURATION FILE

       An Instance Domain equivalence mapping file conforms to the
       following syntax:
       1.  Lines beginning with optional white space, followed by ``#''
           are considered comments.
       2.  Blank lines are ignored.
       3.  Each remaining line defines one `equivalence map'' with a
           list of white-space separated instance domains, each
           consisting of a number (the domain number), a period ``.''
           and a number (the serial number).  As a special case to
           ``match all serial numbers'', the serial number part can be
           ``*''.

       The format of a pmInDom demands that a domain number is in the
       range 0 to 511, and a numeric serial number is in the range 0 to
       4194303.

DIAGNOSTICS AND RETURN VALUES

       The return value is 1 if the Instance Domains are equivalent,
       else 0 if they are not.  In rare cases a return value of -1 is
       used to indicate some problem (reported on standard error) in
       opening or parsing the configuration file.

SEE ALSO

       pmLookupInDom(3) and PMAPI(3).

COLOPHON

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨http://www.pcp.io/⟩.  If you have a bug report for this manual
       page, send it to pcp@groups.io.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/performancecopilot/pcp.git⟩ on 2024-06-14.
       (At that time, the date of the most recent commit that was found
       in the repository was 2024-06-14.)  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
       man-pages@man7.org

Performance Co-Pilot               PCP                   PMEQUIVINDOM(3)