pmns(5) — Linux manual page


PMNS(5)                    File Formats Manual                   PMNS(5)

NAME         top

       PMNS - the performance metrics name space

SYNOPSIS         top


DESCRIPTION         top

       When using the Performance Metrics Programming Interface (PMAPI)
       of the Performance Co-Pilot (PCP), performance metrics are
       identified by an external name in a hierarchic Performance
       Metrics Name Space (PMNS), and an internal identifier, the
       Performance Metric Identifier (PMID).

       A PMNS specifies the association between a metric's name and its

       A PMNS is defined on one or more ASCII source files.

       Loading of a PMNS is done by calling pmLoadNameSpace(3) or

       As of Version 3.10.3 of PCP, by default duplicate names for the
       same PMID are allowed in the PMNS, although
       pmLoadASCIINameSpace(3) provides an alternative interface with
       user-defined control over the processing of duplicate names in
       the PMNS.  The external format for a PMNS conforms to the syntax
       and semantics described in the following sections.

       There is one default PMNS in the files below $PCP_VAR_DIR/pmns,
       although users and application developers are free to create and
       use alternate PMNS's.  For an example of this, see the PCP
       Tutorial in $PCP_DEMOS_DIR/Tutorial.

       Although an application can call pmLoadNameSpace(3), normally
       this is only done directly for the -n command line option where
       an explicit root PMNS file is specified.  Since PCP version 2
       uses a distributed PMNS (see below), an application can extract
       PMNS information from a host's PMCD or an archive.  If the PMNS
       source is a version 1 archive (see PCPIntro(1)), however, then
       the local PMNS will be loaded using the path specified by the
       environment variable PMNS_DEFAULT.


       In PCP version 1, the PMNS functions in the API all operated on a
       PMNS loaded locally from a file. Since PCP version 2, however,
       PMNS functions may get the PMNS information remotely from a PMCD
       or directly from the meta data of an archive.


       The PMNS specification is initially passed through pmcpp(1).
       This means the following facilities may be used in the

       +  C-style comments

       +  #include directives

       +  #define directives and macro substitution

       +  conditional processing via #ifdef ...  #endif, etc.

       When pmcpp(1) is executed, the ``standard'' include directories
       are the current directory and $PCP_VAR_DIR/pmns.

       The preprocessing with pmcpp(1) may be omitted in some cases
       where the PMNS is known to not contain any C-style comments,
       preprocessor directives or macros.  Refer to the descriptions of
       pmLoadASCIINameSpace(3) and pmLoadNameSpace(3) for details.

SYNTAX         top

       The general syntax for a non-leaf node in the PMNS is as follows

       pathname {
               name      [pmid]

       Where pathname is the full pathname from the root of the PMNS to
       this non-leaf node, with each component in the pathname separated
       by a ``.''.  The root node for the PMNS must have the special
       name ``root'', but the common prefix ``root.'' must be omitted
       from all pathnames.  Each component in the pathname is drawn from
       the ASCII(7) character set, beginning with an alphabetic
       character, and followed by zero or more characters drawn from the
       alphabetics, the digits and the underscore ``_'') character.  For
       alphabetic characters in a pathname component, upper and lower
       case are distinguished.

       Non-leaf nodes in the PMNS may be defined in any order.

       The descendent nodes are defined by the set of names, relative to
       the pathname of their parent non-leaf node.  For the descendent
       nodes, leaf nodes have a pmid specification, non-leaf nodes do
       not.  The syntax for the pmid specification has been chosen to
       help manage the allocation of PMIDs across disjoint and
       autonomous domains of administration and implementation.  Each
       pmid consists of 3 integer parts, separated by colons, e.g.
       14:27:11.  This hierarchic numbering scheme is intended to mirror
       the implementation hierarchy of performance metric domain,
       metrics cluster (data structure or operational similarity) and
       individual metric.  In practice, the two leading components are
       likely to be macros in the PMNS specification source, and
       pmcpp(1) will convert the macros to integers.  These macros for
       the initial components of the pmid are likely to be defined
       either in a standard include file, e.g.
       $PCP_VAR_DIR/pmns/stdpmid, or in the current source file.

       To support dynamic metrics, where the existence of a metric is
       known to a PMDA, but not visible in the PMNS, a variant syntax
       for the pmid is supported, namely a domain number followed by
       asterisks for the other components of the pmid, e.g. 14:*:*.  The
       corresponding metric name forms the root of a subtree of dynamic
       metric names defined in the corresponding PMDA as identified by
       the domain number.

       The current allocation of the high-order (PMD or domain)
       component of PMIDs is as follows.
           │  Range  │                 Allocation                 │
           │       0 │ reserved                                   │
           │   1-384 │ production PMDAs from PCP packages         │
           │ 385-510 │ end-user PMDAs (allocate from high to low) │
           │     511 │ reserved for dynamic PMNS entries          │

EXAMPLE         top

       #define KERNEL 1
       #define FOO 387
       root {
           dynamic     FOO:*:*

       #define NETWORK 26
       network {
           intrate     KERNEL:NETWORK:1

       network.packetrate {
           in          KERNEL:NETWORK:35
           out         KERNEL:NETWORK:36

       #define CPU 10
       cpu {
           syscallrate KERNEL:CPU:10

       #define USER 20
       #define SYSTEM 21
       #define IDLE 22

       cpu.util {
           user        KERNEL:CPU:USER
           sys         KERNEL:CPU:SYSTEM
           idle        KERNEL:CPU:IDLE

SEE ALSO         top

       PCPIntro(1), pmcd(1), pmcpp(1), PCPIntro(3), PMAPI(3),
       pmErrStr(3), pmGetConfig(3), pmLoadASCIINameSpace(3),
       pmLoadNameSpace(3), pcp.conf(5) and pcp.env(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 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

Performance Co-Pilot               PCP                           PMNS(5)

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