Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

Synopsis

Description

jmap

prints
memory usage
information for a local or remote Java process or a Java core file.
Depending on the option it is invoked with,

jmap
displays one of four memory usage reports. See the Options section
for details.

jmap can be started in three ways:

• Specify the process id of a Java process running locally to obtain
  configuration information about it. See

  jps to
  list local processes.

• To obtain post-mortem configuration information from a core file,
  specify the java executable that produced the core file and the core
  file itself on the command line.

• To obtain configuration information about a Java process running
  remotely, specify the name of the remote host, optionally prefixed by
  a remote process name and @ sign.

  jsadebugd must
  be running on the remote host.

In Java 5.0,

jmap is experimental, unsupported,
and not available on all platforms.

Options

When invoked with no options,

jmap prints a
memory map of the shared objects or libraries loaded by the VM. Other
reports can be produced by using the options below. These options are
mutually exclusive; only one may be specified.

-heap

Displays a summary of heap memory usage.

-help, -h

Prints a help message.

-histo

Displays a histogram of heap usage by class.

-permstat

Displays memory used by loaded classes, grouped by class loader.

See also

jps ,

jsadebugd