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
17             immediately 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
22             on a machine, jps(1) 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(1)) 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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46
47       NOTE: This utility is unsupported and may or may not  be  available  in
48       future  versions of the JDK. In Windows Systems where dbgeng.dll is not
49       present, 'Debugging Tools For Windows' needs to be  installed  to  have
50       these tools working. Also, PATH environment variable should contain the
51       location of jvm.dll used by the target process  or  the  location  from
52       which the Crash Dump file was produced.
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54       For example, set PATH=<jdk>\jre\bin\client;%PATH%
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OPTIONS

57          <no option>
58             When  no  option  is used jmap prints shared object mappings. For
59             each shared object loaded in the target VM,  start  address,  the
60             size  of the mapping, and the full path of the shared object file
61             are printed. This is similar to the Solaris pmap utility.
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63          -dump:[live,]format=b,file=<filename>
64             Dumps the Java heap in hprof binary format to filename. The  live
65             suboption is optional. If specified, only the live objects in the
66             heap are dumped. To browse the heap dump,  you  can  use  jhat(1)
67             (Java Heap Analysis Tool) to read the generated file.
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69          -finalizerinfo
70             Prints information on objects awaiting finalization.
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72          -heap
73             Prints  a heap summary. GC algorithm used, heap configuration and
74             generation wise heap usage are printed.
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76          -histo[:live]
77             Prints a histogram of the heap. For each Java  class,  number  of
78             objects,  memory  size  in bytes, and fully qualified class names
79             are printed. VM internal class names are printed with '*' prefix.
80             If  the  live  suboption  is  specified,  only  live  objects are
81             counted.
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83          -permstat
84             Prints class loader wise statistics of  permanent  generation  of
85             Java  heap.  For  each class loader, its name, liveness, address,
86             parent class loader, and the number and size of  classes  it  has
87             loaded  are printed. In addition, the number and size of interned
88             Strings are printed.
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90          -F Force. Use with jmap -dump or jmap -histo option if the pid  does
91             not respond. The live suboption is not supported in this mode.
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93          -h Prints a help message.
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95          -help
96             Prints a help message.
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98          -J<flag>
99             Passes <flag> to the Java virtual machine on which jmap is run.
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SEE ALSO

103          o pmap(1)
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105          o jhat(1)
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107          o jps(1)
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109          o jsadebugd(1)
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112                                  16 Mar 2012                          jmap(1)
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