1jmap(1)                     General Commands Manual                    jmap(1)
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NAME

6       jmap - Memory Map
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SYNOPSIS

9       jmap [ option ] pid
10       jmap [ option ] executable core
11       jmap [ option ] [server-id@]remote-hostname-or-IP
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PARAMETERS

15       option
16          Options are mutually exclusive. Option, if used, should follow imme‐
17          diately after the command name.
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19       pid
20          process id for which the memory map is to be  printed.  The  process
21          must be a Java process. To get a list of Java processes running on a
22          machine, jps may be used.
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24       executable
25          Java executable from which the core dump was produced.
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27       core
28          core file for which the memory map is to be printed.
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30       remote-hostname-or-IP
31          remote debug server's (see jsadebugd) hostname or IP address.
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33       server-id
34          optional unique id, if multiple debug servers  are  running  on  the
35          same remote host.
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DESCRIPTION

39       jmap prints shared object memory maps or heap memory details of a given
40       process or core file or a remote debug server. If the given process  is
41       running  on  a  64-bit  VM,  you may need to specify the -J-d64 option,
42       e.g.:
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44          jmap -J-d64 -heap pid
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47       NOTE - This utility is unsupported and may or may not be  available  in
48       future versions of the JDK.
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51       The only forms of jmap available on the Windows platform are
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54          jmap -dump:<dump-options> pid
55       and
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58          jmap -histo[:live] pid
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OPTIONS

61       <no
62          option>  When  no option is used jmap prints shared object mappings.
63          For each shared object loaded in the target VM, start  address,  the
64          size of the mapping, and the full path of the shared object file are
65          printed. This is similar to the Solaris pmap utility.
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67       -dump:[live,]format=b,file=<filename>
68          Dumps the Java heap in hprof binary format  to  filename.  The  live
69          suboption  is  optional.  If specified, only the live objects in the
70          heap are dumped. To browse the heap dump, you  can  use  jhat  (Java
71          Heap Analysis Tool) to read the generated file.
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73       -finalizerinfo
74          Prints information on objects awaiting finalization.
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76       -heap
77          Prints  a  heap  summary.  GC algorithm used, heap configuration and
78          generation wise heap usage are printed.
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80       -histo[:live]
81          Prints a histogram of the heap.  For  each  Java  class,  number  of
82          objects,  memory  size in bytes, and fully qualified class names are
83          printed. VM internal class names are printed with '*' prefix. If the
84          live suboption is specified, only live objects are counted.
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86       -permstat
87          Prints  class loader wise statistics of permanent generation of Java
88          heap. For each class loader, its  name,  liveness,  address,  parent
89          class  loader,  and the number and size of classes it has loaded are
90          printed. In addition, the number and size of  interned  Strings  are
91          printed.
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93       -F Force. Use with jmap -dump or jmap -histo option if the pid does not
94          respond. The live suboption is not supported in this mode.
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96       -h Prints a help message.
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98       -help
99          Prints a help message.
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101       -J<flag>
102          Passes <flag> to the Java virtual machine on which jmap is run.
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SEE ALSO

106          * pmap (1)
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108          * jhat
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110          * jps
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112          * jsadebugd
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115                                  05 Aug 2006                          jmap(1)