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 /proc/meminfo).

OPTIONS         top

       The available command line options are:

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

       -c count, --samples=count, --count=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

       -l, --lohi
            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, --seconds=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

       For environment variables affecting PCP tools, see

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 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                       PCP-FREE(1)

Pages that refer to this page: pcp(1)