PMAP(1) User Commands PMAP(1)

pmap - display information about the address space of a process

/usr/bin/pmap [-rslF] [-A address_range] [pid | core]...

/usr/bin/pmap -L [-rslF] [-A address_range] [pid] ...

/usr/bin/pmap -x [-aslF] [-A address_range] [pid | core]...

/usr/bin/pmap -S [-alF] [-A address_range] [pid | core]...

The pmap utility prints information about the address space of a process.

The following options are supported:

-a

Prints anonymous and swap reservations for shared mappings.

-A address_range

Specifies the subrange of address space to display. address_range is specified in one of the following forms:

start_addr

A single address limits the output to the segment (or the page if the -L option is present) containing that address. If the specified address corresponds to the starting address of a segment, the output always includes the whole segment even when the -L option is specified.

start_addr,

An address followed by comma without the end address limits the output to all segments (or pages if the -L option is present) starting from the one containing the specified address.

start_addr,end_addr

An address range specified by the start address and end addresses limits the output to all segments (or pages if the -L option is present) starting from the segment or page containing the start address through the segment or page containing the end address.

,end_addr

An address range started with comma without the start address limits the output to all segments (or pages if the -L option is present) starting from the first one present until the segment (or page if the -L option is present) containing the specified address.

-F

Force. Grabs the target process even if another process has control.

See USAGE.

-l

Shows unresolved dynamic linker map names.

-L

Prints lgroup containing physical memory that backs virtual memory.

-r

Prints the process's reserved addresses.

-s

Prints HAT page size information.

-S

Displays swap reservation information per mapping. See USAGE for more information.

-x

Displays additional information per mapping. See USAGE for more information.

The pmap utility prints information about the address space of a process.

Process Mappings


/usr/bin/pmap [ -rslF ] [-A address_range] [ pid | core ] ...

By default, pmap displays all of the mappings in the virtual address order they are mapped into the process. The mapping size, flags, and mapped object name are shown.

The -A option can be used to limit the output to a specified address range. The specified addresses are rounded up or down to a segment boundary and the output includes the segments bounded by those addresses.

Process Lgroup Mappings


/usr/bin/pmap -L [ -rslF ] [-A address_range] pid ...

The -L option can be used to determine the lgroup containing the physical memory backing the specified virtual memory. When used with the -A option, the specified addresses are rounded up or down to a page boundary and the output is limited to the page or pages bounded by those addresses.

This can be used in conjunction with plgrp(1) to discover whether the home lgroup of a thread of interest is the same as where the memory is located and whether there should be memory locality for the thread. The lgrpinfo(1) command can also be useful with this pmap option. It displays the lgroup hierarchy, contents, and characteristics which gives more information about the lgroups that the memory is distributed across and their relationship to each other and any other lgroups of interest.

In addition, the thread and memory placement can be changed by using plgrp(1), pmadvise(1), or madv.so.1(1).

Process anon/locked mapping details


/usr/bin/pmap -x [ -aslF ] [-A address_range] [ pid | core ] ...

The -x option displays additional information per mapping. The size of each mapping, the amount of resident physical memory (RSS), the amount of anonymous memory, and the amount of memory locked is shown with this option. This does not include anonymous memory taken by kernel address space due to this process.

Swap Reservations


/usr/bin/pmap -S [ -alF ] [-A address_range] [ pid | core ] ...

The -S option displays swap reservation information per mapping.

Caution should be exercised when using the -F flag. Imposing two controlling processes on one victim process can lead to chaos. Safety is assured only if the primary controlling process, typically a debugger, has stopped the victim process and the primary controlling process is doing nothing at the moment of application of the proc tool in question.

One line of output is printed for each mapping within the process, unless the -s or -L option is specified. With the -s option, one line is printed for a contiguous mapping of each hardware translation page size. With the -L option one line is printed for a contiguous mapping belonging to the same lgroup. With both -L and -s options, one line is printed for a contiguous mapping of each hardware translation page size belonging to the same lgroup. The column headings are shown in parentheses below.

Virtual Address (Address)

The first column of output represents the starting virtual address of each mapping. Virtual addresses are displayed in ascending order.

Virtual Mapping Size (Kbytes)

The virtual size in kilobytes of each mapping.

Resident Physical Memory (RSS)

The amount of physical memory in kilobytes that is resident for each mapping, including that which is shared with other address spaces.

Anonymous Memory (Anon)

The number of pages, counted by using the system page size, of anonymous memory associated with the specified mapping. Anonymous memory shared with other address spaces is not included, unless the -a option is specified.

Anonymous memory is reported for the process heap, stack, for 'copy on write' pages with mappings mapped with MAP_PRIVATE (see mmap(2)).

Locked (Locked)

The number of pages locked within the mapping. Typical examples are memory locked with mlock() and System V shared memory created with SHM_SHARE_MMU.

Permissions/Flags (Mode)

The virtual memory permissions are shown for each mapping. Valid permissions are:

r:

The mapping can be read by the process.

w:

The mapping can be written by the process.

x:

Instructions that reside within the mapping can be executed by the process.

Flags showing additional information for each mapping can be displayed:

s:

The mapping is shared such that changes made in the observed address space are committed to the mapped file, and are visible from all other processes sharing the mapping.

R:

Swap space is not reserved for this mapping. Mappings created with MAP_NORESERVE and System V ISM shared memory mappings do not reserve swap space.

*:

The data for the mapping is not present in the core file (only applicable when applied to a core file). See coreadm(8) for information on configuring core file content.

Lgroup (Lgrp)

The lgroup containing the physical memory that backs the specified mapping.

Mapping Name (Mapped File)

A descriptive name for each mapping. The following major types of names are displayed for mappings:
A mapped file: For mappings between a process and a file, the pmap command attempts to resolve the file name for each mapping. If the file name cannot be resolved, pmap displays the major and minor number of the device containing the file, and the file system inode number of the file.
Anonymous memory: Memory not relating to any named object or file within the file system is reported as [ anon ].

The pmap command displays common names for certain known anonymous memory mappings:

[ heap ]

The mapping is the process heap.

[ stack ]

The mapping is the main stack.

[ stack tid=n ]

The mapping is the stack for thread n.

[ altstack tid=n ]

The mapping is used as the alternate signal stack for thread n.

If the common name for the mapping is unknown, pmap displays [ anon ] as the mapping name.

System V Shared Memory: Mappings created using System V shared memory system calls are reported with the names shown below:

shmid=n:

The mapping is a System V shared memory mapping. The shared memory identifier that the mapping was created with is reported.

ism shmid=n:

The mapping is an "Intimate Shared Memory" variant of System V shared memory. ISM mappings are created with the SHM_SHARE_MMU flag set, in accordance with shmat(2) (see shmop(2)).

dism shmid=n:

The mapping is a pageable variant of ISM. Pageable ISM is created with the SHM_PAGEABLE flag set in accordance with shmat(2) (see shmop(2)).

Other: Mappings of other objects, including devices such as frame buffers. No mapping name is shown for other mapped objects.

Page Size (Pgsz)

The page size in kilobytes that is used for hardware address translation for this mapping. See memcntl(2) for further information.

Swap Space (Swap)

The amount of swap space in kilobytes that is reserved for this mapping. That is, swap space that is deducted from the total available pool of reservable swap space that is displayed with the command swap -s. See swap(8).

Example 1 Displaying Process Mappings

By default, pmap prints one line for each mapping within the address space of the target process. The following example displays the address space of a typical bourne shell:


example$ pmap 102905
102905:    sh
00010000    192K r-x--  /usr/bin/ksh
00040000      8K rwx--  /usr/bin/ksh
00042000     40K rwx--    [ heap ]
FF180000    664K r-x--  /usr/lib/libc.so.1
FF236000     24K rwx--  /usr/lib/libc.so.1
FF23C000      8K rwx--  /usr/lib/libc.so.1
FF250000      8K rwx--    [ anon ]
FF260000     16K r-x--  /usr/lib/en_US.ISO8859-1.so.2
FF272000     16K rwx--  /usr/lib/en_US.ISO8859-1.so.2
FF280000    560K r-x--  /usr/lib/libnsl.so.1
FF31C000     32K rwx--  /usr/lib/libnsl.so.1
FF324000     32K rwx--  /usr/lib/libnsl.so.1
FF340000     16K r-x--  /usr/lib/libc_psr.so.1
FF350000     16K r-x--  /usr/lib/libmp.so.2
FF364000      8K rwx--  /usr/lib/libmp.so.2
FF380000     40K r-x--  /usr/lib/libsocket.so.1
FF39A000      8K rwx--  /usr/lib/libsocket.so.1
FF3A0000      8K r-x--  /usr/lib/libdl.so.1
FF3B0000      8K rwx--    [ anon ]
FF3C0000    152K r-x--  /usr/lib/ld.so.1
FF3F6000      8K rwx--  /usr/lib/ld.so.1
FFBFC000     16K rw---    [ stack ]


 total     1880K

Example 2 Displaying Memory Allocation and Mapping Types

The -x option can be used to provide information about the memory allocation and mapping types per mapping. The amount of resident, non-shared anonymous, and locked memory is shown for each mapping:


example$ pmap -x 102908
102908:   sh
Address   Kbytes     RSS    Anon  Locked Mode   Mapped File
00010000      88      88       -       - r-x--  sh
00036000       8       8       8       - rwx--  sh
00038000      16      16      16       - rwx--    [ heap ]
FF260000      16      16       -       - r-x--  en_US.ISO8859-1.so.2
FF272000      16      16       -       - rwx--  en_US.ISO8859-1.so.2
FF280000     664     624       -       - r-x--  libc.so.1
FF336000      32      32       8       - rwx--  libc.so.1
FF360000      16      16       -       - r-x--  libc_psr.so.1
FF380000      24      24       -       - r-x--  libgen.so.1
FF396000       8       8       -       - rwx--  libgen.so.1
FF3A0000       8       8       -       - r-x--  libdl.so.1
FF3B0000       8       8       8       - rwx--    [ anon ]
FF3C0000     152     152       -       - r-x--  ld.so.1
FF3F6000       8       8       8       - rwx--  ld.so.1
FFBFE000       8       8       8       - rw---    [ stack ]
--------   -----   -----   -----   ------
total Kb    1072    1032      56       -

The amount of incremental memory used by each additional instance of a process can be estimated by using the resident and anonymous memory counts of each mapping.

In the above example, the bourne shell has a resident memory size of 1032Kbytes. However, a large amount of the physical memory used by the shell is shared with other instances of shell. Another identical instance of the shell shares physical memory with the other shell where possible, and allocates anonymous memory for any non-shared portion. In the above example, each additional bourne shell uses approximately 56Kbytes of additional physical memory.

A more complex example shows the output format for a process containing different mapping types. In this example, the mappings are as follows:


0001000: Executable text, mapped from 'maps' program
0002000: Executable data, mapped from 'maps' program
0002200: Program heap
0300000: A mapped file, mapped MAP_SHARED
0400000: A mapped file, mapped MAP_PRIVATE
0500000: A mapped file, mapped MAP_PRIVATE | MAP_NORESERVE
0600000: Anonymous memory, created by mapping /dev/zero
0700000: Anonymous memory, created by mapping /dev/zero


         with MAP_NORESERVE
0800000: A DISM shared memory mapping, created with SHM_PAGEABLE


         with 8MB locked via mlock(3C)
0900000: A DISM shared memory mapping, created with SHM_PAGEABLE,


         with 4MB of its pages touched.
0A00000: A DISM shared memory mapping, created with SHM_PAGEABLE,


         with none of its pages touched.
0B00000: An ISM shared memory mapping, created with SHM_SHARE_MMU


example$ pmap -x 15492
15492:  ./maps


 Address  Kbytes     RSS    Anon  Locked Mode   Mapped File
00010000       8       8       -       - r-x--  maps
00020000       8       8       8       - rwx--  maps
00022000   20344   16248   16248       - rwx--    [ heap ]
03000000    1024    1024       -       - rw-s-  dev:0,2 ino:4628487
04000000    1024    1024     512       - rw---  dev:0,2 ino:4628487
05000000    1024    1024     512       - rw--R  dev:0,2 ino:4628487
06000000    1024    1024    1024       - rw---    [ anon ]
07000000     512     512     512       - rw--R    [ anon ]
08000000    8192    8192       -    8192 rwxs-    [ dism shmid=0x5]
09000000    8192    4096       -       - rwxs-    [ dism shmid=0x4]
0A000000    8192    8192       -    8192 rwxsR    [ ism shmid=0x2 ]
0B000000    8192    8192       -    8192 rwxsR    [ ism shmid=0x3 ]
FF280000     680     672       -       - r-x--  libc.so.1
FF33A000      32      32      32       - rwx--  libc.so.1
FF390000       8       8       -       - r-x--  libc_psr.so.1
FF3A0000       8       8       -       - r-x--  libdl.so.1
FF3B0000       8       8       8       - rwx--    [ anon ]
FF3C0000     152     152       -       - r-x--  ld.so.1
FF3F6000       8       8       8       - rwx--  ld.so.1
FFBFA000      24      24      24       - rwx--    [ stack ]
-------- ------- ------- ------- -------
total Kb   50464   42264   18888   16384

Example 3 Displaying Page Size Information

The -s option can be used to display the hardware translation page sizes for each portion of the address space. (See memcntl(2) for further information on illumos multiple page size support).

In the example below, we can see that the majority of the mappings are using an 8K-Byte page size, while the heap is using a 4M-Byte page size.

Notice that non-contiguous regions of resident pages of the same page size are reported as separate mappings. In the example below, the libc.so library is reported as separate mappings, since only some of the libc.so text is resident:


example$ pmap -xs 15492
15492:  ./maps


 Address  Kbytes     RSS    Anon  Locked Pgsz Mode   Mapped File
00010000       8       8       -       -   8K r-x--  maps
00020000       8       8       8       -   8K rwx--  maps
00022000    3960    3960    3960       -   8K rwx--    [ heap ]
00400000    8192    8192    8192       -   4M rwx--    [ heap ]
00C00000    4096       -       -       -    - rwx--    [ heap ]
01000000    4096    4096    4096       -   4M rwx--    [ heap ]
03000000    1024    1024       -       -   8K rw-s-  dev:0,2 ino:4628487
04000000     512     512     512       -   8K rw---  dev:0,2 ino:4628487
04080000     512     512       -       -    - rw---  dev:0,2 ino:4628487
05000000     512     512     512       -   8K rw--R  dev:0,2 ino:4628487
05080000     512     512       -       -    - rw--R  dev:0,2 ino:4628487
06000000    1024    1024    1024       -   8K rw---    [ anon ]
07000000     512     512     512       -   8K rw--R    [ anon ]
08000000    8192    8192       -    8192    - rwxs-    [ dism shmid=0x5 ]
09000000    4096    4096       -       -   8K rwxs-    [ dism shmid=0x4 ]
0A000000    4096       -       -       -    - rwxs-    [ dism shmid=0x2 ]
0B000000    8192    8192       -    8192   4M rwxsR    [ ism shmid=0x3 ]
FF280000     136     136       -       -   8K r-x--  libc.so.1
FF2A2000     120     120       -       -    - r-x--  libc.so.1
FF2C0000     128     128       -       -   8K r-x--  libc.so.1
FF2E0000     200     200       -       -    - r-x--  libc.so.1
FF312000      48      48       -       -   8K r-x--  libc.so.1
FF31E000      48      40       -       -    - r-x--  libc.so.1
FF33A000      32      32      32       -   8K rwx--  libc.so.1
FF390000       8       8       -       -   8K r-x--  libc_psr.so.1
FF3A0000       8       8       -       -   8K r-x--  libdl.so.1
FF3B0000       8       8       8       -   8K rwx--    [ anon ]
FF3C0000     152     152       -       -   8K r-x--  ld.so.1
FF3F6000       8       8       8       -   8K rwx--  ld.so.1
FFBFA000      24      24      24       -   8K rwx--    [ stack ]


     -------- ------- ------- ------- -------
total Kb   50464   42264   18888   16384

Example 4 Displaying Swap Reservations

The -S option can be used to describe the swap reservations for a process. The amount of swap space reserved is displayed for each mapping within the process. Swap reservations are reported as zero for shared mappings, since they are accounted for only once system wide.


example$ pmap -S 15492
15492:  ./maps


 Address  Kbytes    Swap Mode   Mapped File
00010000       8       - r-x--  maps
00020000       8       8 rwx--  maps
00022000   20344   20344 rwx--    [ heap ]
03000000    1024       - rw-s-  dev:0,2 ino:4628487
04000000    1024    1024 rw---  dev:0,2 ino:4628487
05000000    1024     512 rw--R  dev:0,2 ino:4628487
06000000    1024    1024 rw---    [ anon ]
07000000     512     512 rw--R    [ anon ]
08000000    8192       - rwxs-    [ dism shmid=0x5]
09000000    8192       - rwxs-    [ dism shmid=0x4]
0A000000    8192       - rwxs-    [ dism shmid=0x2]
0B000000    8192       - rwxsR    [ ism shmid=0x3]
FF280000     680       - r-x--  libc.so.1
FF33A000      32      32 rwx--  libc.so.1
FF390000       8       - r-x--  libc_psr.so.1
FF3A0000       8       - r-x--  libdl.so.1
FF3B0000       8       8 rwx--    [ anon ]
FF3C0000     152       - r-x--  ld.so.1
FF3F6000       8       8 rwx--  ld.so.1
FFBFA000      24      24 rwx--    [ stack ]
-------- ------- -------
total Kb   50464   23496

The swap reservation information can be used to estimate the amount of virtual swap used by each additional process. Each process consumes virtual swap from a global virtual swap pool. Global swap reservations are reported by the 'avail' field of the swap(8) command.

Example 5 Labeling Stacks in a Multi-threaded Process


example$ pmap 121969
121969: ./stacks
00010000       8K r-x--  /tmp/stacks
00020000       8K rwx--  /tmp/stacks
FE8FA000       8K rwx-R    [ stack tid=11 ]
FE9FA000       8K rwx-R    [ stack tid=10 ]
FEAFA000       8K rwx-R    [ stack tid=9 ]
FEBFA000       8K rwx-R    [ stack tid=8 ]
FECFA000       8K rwx-R    [ stack tid=7 ]
FEDFA000       8K rwx-R    [ stack tid=6 ]
FEEFA000       8K rwx-R    [ stack tid=5 ]
FEFFA000       8K rwx-R    [ stack tid=4 ]
FF0FA000       8K rwx-R    [ stack tid=3 ]
FF1FA000       8K rwx-R    [ stack tid=2 ]
FF200000      64K rw---    [ altstack tid=8 ]
FF220000      64K rw---    [ altstack tid=4 ]
FF240000     112K rw---    [ anon ]
FF260000      16K rw---    [ anon ]
FF270000      16K r-x--  /usr/platform/sun4u/lib/libc_psr.so.1
FF280000     672K r-x--  /usr/lib/libc.so.1
FF338000      24K rwx--  /usr/lib/libc.so.1
FF33E000       8K rwx--  /usr/lib/libc.so.1
FF35A000       8K rwxs-    [ anon ]
FF360000     104K r-x--  /usr/lib/libthread.so.1
FF38A000       8K rwx--  /usr/lib/libthread.so.1
FF38C000       8K rwx--  /usr/lib/libthread.so.1
FF3A0000       8K r-x--  /usr/lib/libdl.so.1
FF3B0000       8K rwx--    [ anon ]
FF3C0000     152K r-x--  /usr/lib/ld.so.1
FF3F6000       8K rwx--  /usr/lib/ld.so.1
FFBFA000      24K rwx--    [ stack ]


 total      1400K

Example 6 Displaying lgroup Memory Allocation

The following example displays lgroup memory allocation by mapping:


example$ pmap -L `pgrep nscd`
100095: /usr/sbin/nscd
00010000       8K r-x--   2 /usr/sbin/nscd
00012000      48K r-x--   1 /usr/sbin/nscd
0002E000       8K rwx--   2 /usr/sbin/nscd
00030000      16K rwx--   2   [ heap ]
00034000       8K rwx--   1   [ heap ]


         .


         .


         .
FD80A000      24K rwx--   2   [ anon ]
FD820000       8K r-x--   2 /lib/libmd5.so.1
FD840000      16K r-x--   1 /lib/libmp.so.2
FD860000       8K r-x--   2 /usr/lib/straddr.so.2
FD872000       8K rwx--   1 /usr/lib/straddr.so.2
FD97A000       8K rw--R   1   [ stack tid=24 ]
FD990000       8K r-x--   2 /lib/nss_nis.so.1
FD992000      16K r-x--   1 /lib/nss_nis.so.1
FD9A6000       8K rwx--   1 /lib/nss_nis.so.1
FD9C0000       8K rwx--   2   [ anon ]
FD9D0000       8K r-x--   2 /lib/nss_files.so.1
FD9D2000      16K r-x--   1 /lib/nss_files.so.1
FD9E6000       8K rwx--   2 /lib/nss_files.so.1
FDAFA000       8K rw--R   2   [ stack tid=23 ]
FDBFA000       8K rw--R   1   [ stack tid=22 ]
FDCFA000       8K rw--R   1   [ stack tid=21 ]
FDDFA000       8K rw--R   1   [ stack tid=20 ]


    .


    .


    .
FEFFA000       8K rw--R   1   [ stack tid=2 ]
FF000000       8K rwx--   2   [ anon ]
FF004000      16K rwx--   1   [ anon ]
FF00A000      16K rwx--   1   [ anon ]


    .


    .


    .
FF3EE000       8K rwx--   2 /lib/ld.so.1
FFBFE000       8K rw---   2   [ stack ]


 total      2968K

The following exit values are returned:

0

Successful operation.

non-zero

An error has occurred.

/proc/*

process files

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability See below.

The command syntax is Evolving. The -L option and the output formats are Unstable.

ldd(1), lgrpinfo(1), madv.so.1(1), mdb(1), plgrp(1), pmadvise(1), proc(1), ps(1), memcntl(2), meminfo(2), mmap(2), shmop(2), dlopen(3C), proc(5), attributes(7), coreadm(8), prstat(8), swap(8)

July 17, 2023 OmniOS