How to read the data in memray

[benhgm]

Hello there, I would like to use memray, but I am confused over how it works. I have some questions here:

1. What do the green, yellow and white cells in the flamegraph represent?
2. For checking memory leaks, I noticed that the values for the report with --leaks flag set and without it are the same. How do I make sense of this information?
   Thank you so much for any advice!

[pradyunsg]

1. The colors are based on the extension of the file that contains the line of code pointed to, by that frame. Green is py, Yellow is c/cpp, Grey is "something else".

2. Did you run your application with the PYTHONMALLOC=malloc environment variable set? https://bloomberg.github.io/memray/flamegraph.html#memory-leaks-view

[benhgm]

Thanks @pradyunsg for the advice. I ran my code as follows:

PYTHONMALLOC=malloc memray run --trace-python-allocators script.py

Is this correct? I may have made a mistake

[pablogsal]

Also, did you had a chance to check out the docs regarding this topic: https://bloomberg.github.io/memray/flamegraph.html

[pablogsal]

2. For checking memory leaks, I noticed that the values for the report with --leaks flag set and without it are the same. How do I make sense of this information?

That means that whatever was on the high watermark has been there until the end of the program. As we recommend in several places in the docs, please run with --trace-python-allocators or with the PYTHONMALLOC=malloc environment variable.

[benhgm]

Hi @pablogsal thanks for replying. Yes I did run with PYTHONMALLOC=malloc memray --trace-python-allocators

One noob question, must I run with export PYTHONMALLOC=malloc?

Thank you!

[pablogsal]

One noob question, must I run with export PYTHONMALLOC=malloc?

Likely not because that will affect all processes in your machine (as long as they inherit the environment variable) and that has the side-effect of making everything slower 😉