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>.

Debian                                          01 November 1998                                      MEMSTAT(1)