Prints shared object memory maps or heap memory details for a process, core file, or remote debug server. This command is experimental and unsupported.
jmap [ options ] pid
jmap [ options ] executable core
jmap [ options ] [ pid ] server-id@ ] remote-hostname-or-IP
The process ID for which the memory map is to be printed. The process must be a Java process. To get a list of Java processes running on a machine, use the jps
(1) command.
The Java executable from which the core dump was produced.
The core file for which the memory map is to be printed.
The remote debug server hostname
or IP
address. See jsadebugd
(1).
An optional unique ID to use when multiple debug servers are running on the same remote host.
When no option is used, the jmap
command prints shared object mappings. For each shared object loaded in the target JVM, the start address, size of the mapping, and the full path of the shared object file are printed. This behavior is similar to the Oracle Solaris pmap
utility.
Dumps the Java heap in hprof
binary format to filename
. The live
suboption is optional, but when specified, only the active objects in the heap are dumped. To browse the heap dump, you can use the jhat
(1) command to read the generated file.
Prints information about objects that are awaiting finalization.
Prints a heap summary of the garbage collection used, the head configuration, and generation-wise heap usage. In addition, the number and size of interned Strings are printed.
Prints a histogram of the heap. For each Java class, the number of objects, memory size in bytes, and the fully qualified class names are printed. The JVM internal class names are printed with an asterisk (*) prefix. If the live
suboption is specified, then only active objects are counted.
Prints class loader wise statistics of Java heap. For each class loader, its name, how active it is, address, parent class loader, and the number and size of classes it has loaded are printed.
Force. Use this option with the jmap -dump
or jmap -histo
option when the pid does not respond. The live
suboption is not supported in this mode.
Prints a help message.
Prints a help message.
Passes flag
to the Java Virtual Machine where the jmap
command is running.