First I would pickup the process with the `smem`. For example, you could use `smem -tas uss` to have an overview.
- `-t` ... shows totals
- `-a` ... auto adjusts the column width
- `-s uss`... sorts the result based on the *uss* column
To see details per process the best way is to use `pmap`. To get detailed information you should use `-X` switch. To get all information that kernel provides you can use `-XX` which usually is an overkill.
To get a 2 seconds refresh monitoring for a *pid* 3120:
`watch -n 2 pmap -X 3120`
**Edit: To actually get a peak** The above helps in monitoring, but it does not show an actual peak. Slipped my mind.
I would personally use `valgrind` with the `massif` tool.
`valgrind --tool=massif --page-as-heap=yes --massif-out-file=evolution_massif.out evolution; grep mem_heap_B evolution_massif.out | sed -e 's/mem_heap_B=\(.*\)/\1/' | sort -g | tail -n 1`
Explanation:
- `--page-as-heap=yes` ... tells massif that it should take all memory instead of just heap
- `--massif-out-file` ... the output file for the *massif* tool
- **evolution** ... the application that should be monitored
The next part is there to find out the maximum number recorded.
The `grep` searches for *mem_heap_B* occurrences. `sed` gets rid of the string `mem_heap_B` so we get only numeric result. The we sort it via `sort -g` which is generic numeric sort and take the biggest number with `tail -n 1` which returns the first line of the sorted numbers.
To display the output file *evolution_massif.out*, you can use `ms_print` post-processing tool for Massif.
It is simply:
`ms_print evolution_massif.out`
The output should look like this (this is first page of the output), where you can see which snapshot was a peak - **10 (peak)**:
```
--------------------------------------------------------------------------------
Command: evolution
Massif arguments: --pages-as-heap=yes --massif-out-file=massif.out
ms_print arguments: massif.out
--------------------------------------------------------------------------------
GB
10.09^ #
| #
| #
| #
| #
| #
| # @:::::@::::::::::::::::@@:::::@:::::@::::::@::::@:::::@::
| # @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::::@:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| @ #::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
| :::@::#::::: @:::::@: :::::::: :::: @@:::::@:::::@::::::@::::@:::::@::
0 +----------------------------------------------------------------------->Gi
0 8.927
Number of snapshots: 97
Detailed snapshots: [7, 10 (peak), 17, 24, 43, 44, 50, 60, 70, 80, 90]
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
0 0 16,384 16,384 0 0
1 149,772,704 393,547,776 393,547,776 0 0
2 243,902,287 398,592,800 398,592,800 0 0
3 396,613,298 558,157,704 558,157,704 0 0
4 504,752,503 638,138,760 638,138,760 0 0
5 604,812,936 639,894,808 639,894,808 0 0
...
```
**Edit to add all children**:
To add all descendants (children) you can add the `--trace-children=yes` option to the `valgrind` command.