Options are mutually exclusive. Option, if used, should follow
immediately after the command name.
pid
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, jps may be used.
executable
Java executable from which the core dump was produced.
core
core file for which the memory map is to be printed.
remote-hostname-or-IP
remote debug server's (see jsadebugd) hostname or IP address.
server-id
optional unique id, if multiple debug servers are running on
the same remote host.
DESCRIPTION
jmap prints shared object memory maps or heap memory
details of a given process or core file or a remote debug server.
If the given process is running on a 64-bit VM, you may need to
specify the -J-d64 option, e.g.:
jmap -J-d64 -heap pid
NOTE: This utility is unsupported and may or
may not be available in future versions of the JDK. In Windows
Systems where dbgeng.dll is not present, 'Debugging Tools
For Windows' needs to be installed to have these tools working.
Also, the PATH environment variable should contain the
location of jvm.dll used by the target process or the
location from which the Crash Dump file was produced.
When no option is used jmap prints
shared object mappings. For each shared object loaded in the target
VM, start address, the size of the mapping, and the full path of
the shared object file are printed. This is similar to the Solaris
pmap utility.
-dump:[live,]format=b,file=<filename>
Dumps the Java heap in hprof binary format to filename. The
live suboption is optional. If specified, only the live
objects in the heap are dumped. To browse the heap dump, you can
use jhat (Java Heap Analysis Tool) to read
the generated file.
-finalizerinfo
Prints information on objects awaiting finalization.
-heap
Prints a heap summary. GC algorithm used, heap configuration
and generation wise heap usage are printed.
-histo[:live]
Prints a histogram of the heap. For each Java class, number of
objects, memory size in bytes, and fully qualified class names are
printed. VM internal class names are printed with '*' prefix. If
the live suboption is specified, only live objects are
counted.
-permstat
Prints class loader wise statistics of permanent generation of
Java heap. For each class loader, its name, liveness, address,
parent class loader, and the number and size of classes it has
loaded are printed. In addition, the number and size of interned
Strings are printed.
-F
Force. Use with jmap -dump or jmap -histo option if the pid
does not respond. The live suboption is not supported in
this mode.
-h
Prints a help message.
-help
Prints a help message.
-J<flag>
Passes <flag> to the Java virtual machine on which jmap
is run.