NAME

       memstat - Identify what's using up virtual memory.

SYNOPSIS

       memstat [-n][-v][-w][-p PID]

DESCRIPTION

       memstat  lists  all accessible processes, executables, and shared libraries that are using
       up virtual memory. To get a complete list memstat has to be run as  root  to  be  able  to
       access the data of all running processes.

       First, the processes are listed.  An amount of memory is shown along with a process ID and
       the name of the executable which the process is running.  The amount of memory shown  does
       not  include shared memory: it only includes memory which is private to that process.  So,
       if a process is using a shared library like libc, the memory used to hold that library  is
       not included.  The memory used to hold the executable's text-segment is also not included,
       since that too is shareable.

       After the processes, the shared objects are listed.  The amount of memory is  shown  along
       with  the  filename  of  the  shared object, followed by a list of the processes using the
       shared object. The memory is listed as the total amount of memory allocated to this object
       throughout  the  whole  namespace.   In  brackets also the amount that is really shared is
       listed.

       Finally, a grand total is shown.  Note that this program shows the amount of virtual  (not
       real) memory used by the various items.

       memstat  gets its input from the /proc filesystem.  This must be compiled into your kernel
       and mounted for memstat to work.  The pathnames shown next to the shared objects are  also
       read  from  /proc  filesystem  if this information is available. If not, memstat scans the
       disk to translate inode information to filesnames.  For this memstat uses a  configuration
       file, /etc/memstat.conf, to determine which directories to scan.  This file should include
       all the major bin and lib directories in your system,  as  well  as  the  /dev  directory.
       These directories are scanned recursively, so that files stored in subdirectories are seen
       by memstat as well.  Note that this traversal of directory trees  significantly  increases
       run time.  Executables or shared objects not found will be listed as ``[dev]:<inode>''.

   Options
       The  -n  switch  causes  inode information to be printed as-is, if no file information was
       given and to not traverse the configured directory trees.

       The -v switch prints version information and exits.

       The -w switch causes a wide printout: lines are not truncated at 80 columns.

       The -p switch causes memstat to only print data gathered from looking at the process  with
       the given PID.

NOTES

       These reports are intended to help identify programs that are using an excessive amount of
       memory, and to reduce overall memory waste.

FILES

       /etc/memstat.conf
       /proc/*/maps

SEE ALSO

       ps(1), top(1), free(1), vmstat(8), lsof(8), /usr/share/doc/memstat/memstat-tutorial.txt.gz

BUGS

       memstat ignores all devices that just map main memory, though this may  cause  memstat  to
       ignore some memory usage.

       Memory used by the kernel itself is not listed.

AUTHOR

       Originally  written  by  Joshua  Yelon  <jyelon@uiuc.edu>  and  patched by Bernd Eckenfels
       <ecki@debian.org>. Taken over and rewritten by Michael Meskes <meskes@debian.org>.