pmdbg(1) — Linux manual page


PMDBG(1)                 General Commands Manual                PMDBG(1)

NAME         top

       pmdbg - report Performance Co-Pilot debug options

SYNOPSIS         top

       pmdbg code ...
       pmdbg -l [-o] [-g]
       pmdbg -D name[,name ...]

DESCRIPTION         top

       The components of the Performance Co-Pilot (PCP) use a global
       mechanism to control diagnostic and debug output.  Historically
       this was a vector of bit-fields but this was later replaced by an
       array of debug options.  All of the bit-field debug controls have
       an equivalent in the new scheme, but some new debug options
       cannot be represented in the old bit-field scheme.

       pmdbg with a -l option prints out all the debug options.  If
       there is no -g and no -o option then the output lists the name of
       each option and some descriptive text.

       With the -l and -g options the descriptive text is replaced with
       an expression that can be used to set or print the corresponding
       debug flag in gdb(1).

       With the -l and -o options the output is for only the old bit-
       fields with the mnemonic and decimal values of each the bit-field
       along with some descriptive text.

       Obviously the -o and -g options are mutually exclusive.

       pmdbg with a -D option parses the list of names(s) using
       __pmParseDebug(3) and reports the corresponding decimal value.
       This use is not required in the new scheme, but for the old bit-
       fields scheme it was useful when debugging and wanting to set the
       internal value of the control vector (pmDebug) via a debugger,
       e.g.  gdb(1).  For the new scheme, the same effect can be
       achieved using the name of the option(s) and calling
       pmSetDebug(3) from within the debugger.

       The alternative usage also relates to the old bit-field scheme
       and the code arguments are values for the debug vector, and the
       bit-fields that are enabled by each of these values is listed.

       Each code may be an integer, a hexadecimal value or a hexadecimal
       value prefixed by either ``0x'' or ``0X''.

       Most applications using the facilities of the PCP support a -D
       name[,name ...]  command-line syntax to enable debug control
       using the name(s) of the desired debug options.

       Alternatively the initial value of the debug control flags may be
       set to either a value N (old scheme) or a comma-separated list if
       option name(s) (new scheme) using the environment variable
       $PCP_DEBUG.  If both mechanisms are used the effect is additive,
       so the resultant flags are those set via $PCP_DEBUG combined with
       those set via any -D command line options.

OPTIONS         top

       The available command line options are:

       -D name, --debug=name
            Parse a comma-separated list of name(s) and report the
            corresponding decimal value(s).

       -l, --list
            List all the debug options.

       -g, --gdb
            Output gdb(1) expressions with -l.

       -o, --old
            Use old-style output format with -l.

       -?, --help
            Display usage message and exit.


       Environment variables with the prefix PCP_ are used to
       parameterize the file and directory names used by PCP.  On each
       installation, the file /etc/pcp.conf contains the local values
       for these variables.  The $PCP_CONF variable may be used to
       specify an alternative configuration file, as described in

SEE ALSO         top

       PCPIntro(1), pmSetDebug(3), pmClearDebug(3), __pmParseDebug(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 2023-12-22.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-12-16.)  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                          PMDBG(1)

Pages that refer to this page: dbpmda(1)pcpintro(1)pmcd(1)pmdaib(1)pmproxy(1)pmda(3)pmdagetoptions(3)pmparsedebug(3)pmprintf(3)pmsetdebug(3)