pcp-free(1) — Linux manual page


PCP-FREE(1)                General Commands Manual               PCP-FREE(1)

NAME         top

       pcp-free - report on free and used memory in the system

SYNOPSIS         top

       pcp [pcp options] free [-bkmgroltVw?]  [-c count] [-s interval]

DESCRIPTION         top

       pcp-free gives a summary display of the total amount of free and used
       physical memory and swap in the system, as well as the caches used by
       the kernel.

       When invoked via the pcp(1) command, the -h/--host, -a/--archive,
       -O/--origin, -s/--samples, -t/--interval, -Z/--timezone and several
       other pcp options become indirectly available, see PCPIntro(1) for
       their descriptions.

       The displayed columns are:

       total  Total installed memory (MemTotal and SwapTotal in

       used   Used memory (calculated as total - free - buffers - cache)

       free   Unused memory (MemFree and SwapFree in /proc/meminfo)

       shared Memory used (mostly) by tmpfs (Shmem in /proc/meminfo)

              Memory used by kernel buffers (Buffers in /proc/meminfo)

       cache  Memory used by the page cache and slabs (Cached and
              SReclaimable in /proc/meminfo)

              Sum of buffers and cache

              Estimation of how much memory is available for starting new
              applications, without swapping.  Unlike the data provided by
              the cache or free fields, this field takes into account page
              cache and also that not all reclaimable memory slabs will be
              reclaimed due to items being in use (MemAvailable in

OPTIONS         top

       The available command line options are:

       -b, --bytes
            Display the amount of memory in bytes.

       -c count, --samples=count
            Terminate the display after count iterations.  See also -s.

       -g, --gigabytes
            Display the amount of memory in gigabytes.

       -k, --kilobytes
            Display the amount of memory in kilobytes.  This is the default.

       -l   Display detailed low and high memory statistics.

       -m, --megabytes
            Display the amount of memory in megabytes.

       -o   Disable the display of a "buffer adjusted" line.  If the -o
            option is not specified, free subtracts buffer memory from the
            used memory and adds it to the free memory reported.

       -r, --terabytes
            Display the amount of memory in terabytes.

       -s delay, --interval=delay
            Activate continuous polling delay seconds apart.  You may
            specify any floating point number for delay, or indeed any valid
            pmParseInterval(3) specification, which includes microsecond
            resolution delay times.  This can be used in conjunction with
            the -c option.

       -t, --total
            Display a line containing the totals.

       -V, --version
            Display version number and exit.

       -w, --wide
            Switch to the wide mode.  The wide mode produces lines longer
            than 80 characters.  In this mode buffers and cache are reported
            in two separate columns.

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

NOTES         top

       pcp-free is inspired by the free(1) command and aims to be command
       line and output compatible with it.


       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 pcp.conf(5).

       For environment variables affecting PCP tools, see pmGetOptions(3).

SEE ALSO         top

       PCPIntro(1), pcp(1), free(1), pmParseInterval(3) and environ(7).

COLOPHON         top

       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
       2020-11-01.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-10-30.)  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                         PCP-FREE(1)

Pages that refer to this page: pcp(1)pcp-summary(1)