mirror of
https://github.com/QubesOS/qubes-doc.git
synced 2024-10-01 01:25:40 -04:00
c2e2d1d793
add warning about running untrusted code
95 lines
2.4 KiB
Markdown
95 lines
2.4 KiB
Markdown
---
|
|
layout: wiki
|
|
title: Profiling
|
|
permalink: /wiki/Profiling/
|
|
---
|
|
|
|
Profiling
|
|
=========
|
|
|
|
This is python profiling primer.
|
|
|
|
For the purpose of this document, `qubes-dev` is name of the domain used for postprocessing profiling stats.
|
|
|
|
Requirements
|
|
------------
|
|
|
|
``` {.wiki}
|
|
yum install gprof2dot graphviz
|
|
git clone http://git.woju.eu/qubes/profiling.git
|
|
```
|
|
|
|
If you profile something on dom0, move `Upload.sh` from repository to dom0:
|
|
|
|
``` {.wiki}
|
|
mkdir -p ~/profiling
|
|
qvm-run -p qubes-dev 'cat ~/profiling/Upload.sh' > ~/profiling/Upload.sh
|
|
```
|
|
|
|
- WARNING: this will obviously be running third party code which is not signed by ITL nor Fedora. You have been warned.
|
|
|
|
Workflow
|
|
--------
|
|
|
|
### Identify function responsible for some slow action
|
|
|
|
You have to select area in which you suspect less than optimal performance. If you do not narrow the area, graphs may be unreadable.
|
|
|
|
### Replace suspect function with probe
|
|
|
|
Replace
|
|
|
|
def foo(self, bar):
|
|
# function content
|
|
|
|
with
|
|
|
|
def foo(self, *args, **kwargs):
|
|
profile.runctx('self.real_foo(*args, **kwargs)', globals(), locals(),
|
|
time.strftime('/home/user/profiling/foo-%Y%m%d-%H%M%S.pstats'))
|
|
|
|
def real_foo(self, bar):
|
|
# function content
|
|
|
|
### Run application
|
|
|
|
Beware that some functions may be called often. For example `qubesmanager/main.py:update_table` gets run once per second. This will produce one pstat file per second.
|
|
|
|
Remember to revert your changes to application afterwards.
|
|
|
|
### Upload statistics
|
|
|
|
If you are in dom0:
|
|
|
|
``` {.wiki}
|
|
cd ~/profiling
|
|
./Upload.sh
|
|
```
|
|
|
|
### Analyse
|
|
|
|
``` {.wiki}
|
|
make
|
|
```
|
|
|
|
For every `${basename}.pstats` this will produce `${basename}.txt` and `${basename}.svg`. SVG contains call graph. Text file contains list of all functions sorted by cumulative execution time. You may also try `make all-png`.
|
|
|
|
``` {.wiki}
|
|
make index.html
|
|
```
|
|
|
|
This creates `index.html` with all SVG graphics linked to TXT files. Ready for upload.
|
|
|
|
``` {.wiki}
|
|
make REMOTE=example.com:public_html/qubes/profiling/ upload
|
|
```
|
|
|
|
Example
|
|
-------
|
|
|
|
This example is from `qubes-manager` (`qubesmanager/main.py`).
|
|
|
|
[![No image "update\_table-20140424-170010.svg" attached to Profiling](/chrome/common/attachment.png "No image "update_table-20140424-170010.svg" attached to Profiling")](/attachment/wiki/Profiling/update_table-20140424-170010.svg)
|
|
|
|
It is apparent than problem is around `get_disk_usage` which calls something via `subprocess.call`. It does it 15 times, probably once per VM.
|