# 9 Notes on memtype parameter in proc.mem items

#### Overview

The **memtype** parameter is supported on Linux, AIX, FreeBSD, and
Solaris platforms.

Three common values of 'memtype' are supported on all of these
platforms: `pmem`, `rss` and `vsize`. Additionally, platform-specific
'memtype' values are supported on some platforms.

#### AIX

See values supported for 'memtype' parameter on AIX in the table.

|Supported value|Description|Source in procentry64 structure|Tries to be compatible with|
|---------------|-----------|-------------------------------|---------------------------|
|vsize (( - default value))|Virtual memory size|pi\_size|<|
|pmem|Percentage of real memory|pi\_prm|ps -o pmem|
|rss|Resident set size|pi\_trss + pi\_drss|ps -o rssize|
|size|Size of process (code + data)|pi\_dvm|"ps gvw" SIZE column|
|dsize|Data size|pi\_dsize|<|
|tsize|Text (code) size|pi\_tsize|"ps gvw" TSIZ column|
|sdsize|Data size from shared library|pi\_sdsize|<|
|drss|Data resident set size|pi\_drss|<|
|trss|Text resident set size|pi\_trss|<|

#### FreeBSD

See values supported for 'memtype' parameter on FreeBSD in the table.

|Supported value|Description|Source in kinfo\_proc structure|Tries to be compatible with|
|---------------|-----------|-------------------------------|---------------------------|
|vsize|Virtual memory size|kp\_eproc.e\_vm.vm\_map.size or ki\_size|ps -o vsz|
|pmem|Percentage of real memory|calculated from rss|ps -o pmem|
|rss|Resident set size|kp\_eproc.e\_vm.vm\_rssize or ki\_rssize|ps -o rss|
|size (( - default value))|Size of process (code + data + stack)|tsize + dsize + ssize|<|
|tsize|Text (code) size|kp\_eproc.e\_vm.vm\_tsize or ki\_tsize|ps -o tsiz|
|dsize|Data size|kp\_eproc.e\_vm.vm\_dsize or ki\_dsize|ps -o dsiz|
|ssize|Stack size|kp\_eproc.e\_vm.vm\_ssize or ki\_ssize|ps -o ssiz|

#### Linux

See values supported for 'memtype' parameter on Linux in the table.

|Supported value|Description|Source in /proc/<pid>/status file|
|---------------|-----------|---------------------------------------|
|vsize (( - default value))|Virtual memory size|VmSize|
|pmem|Percentage of real memory|(VmRSS/total\_memory) \* 100|
|rss|Resident set size|VmRSS|
|data|Size of data segment|VmData|
|exe|Size of code segment|VmExe|
|hwm|Peak resident set size|VmHWM|
|lck|Size of locked memory|VmLck|
|lib|Size of shared libraries|VmLib|
|peak|Peak virtual memory size|VmPeak|
|pin|Size of pinned pages|VmPin|
|pte|Size of page table entries|VmPTE|
|size|Size of process code + data + stack segments|VmExe + VmData + VmStk|
|stk|Size of stack segment|VmStk|
|swap|Size of swap space used|VmSwap|

Notes for Linux:

1.  Not all 'memtype' values are supported by older Linux kernels. For
    example, Linux 2.4 kernels do not support `hwm`, `pin`, `peak`,
    `pte` and `swap` values.
2.  We have noticed that self-monitoring of the Zabbix agent active
    check process with `proc.mem[...,...,...,...,data]` shows a value
    that is 4 kB larger than reported by `VmData` line in the agent's
    /proc/<pid>/status file. At the time of self-measurement the
    agent's data segment increases by 4 kB and then returns to the
    previous size.

#### Solaris

See values supported for 'memtype' parameter on Solaris in the table.

|Supported value|Description|Source in psinfo structure|Tries to be compatible with|
|---------------|-----------|--------------------------|---------------------------|
|vsize (( - default value))|Size of process image|pr\_size|ps -o vsz|
|pmem|Percentage of real memory|pr\_pctmem|ps -o pmem|
|rss|Resident set size<br>It may be underestimated - see rss description in "man ps".|pr\_rssize|ps -o rss|