esp-wifi memory requirements?

[yanshay]

I saw esp-wifi reserves by default 64k for heap memory. That's a big chunk.
I also saw that it's possible to configure the amount of memory it is using in a specific application.

• What does it use so much memory for (well, relative to the amount of memory on the device)?
  I thought it would be for buffers to accept data when the cpu is doing something else (so handling incoming data in interrupts) but in my tests, when I don't give it cpu time frequently enough (I'm using embassy with a task that from time to time needs 200 msec) then traffic gets lots (and I'm listening to very little UDP traffic). So I had to move my wifi related code to the 2nd core to make sure it gets cpu time.

• If I need to reduce that memory (for other needs), how can I estimate how much is required in my specific application?
  My application is listening to UDP traffic, max 10 messages a sec, each a couple of hundred bytes. And then from time to time sending a few of those UDP messages, much less though.

[MabezDev]

Everything is tunable, see tunable.md in the repo. You will need to experiment yourself and figure out values based on your required throughput etc.

[jsprog]

Where can I find tunable.md file?

[JurajSadel]

It was moved to the esp-wifi docs with esp-rs/esp-hal#2156 being merged. This change hasn't been released yet so to see the parameters you need to build the docs locally for now, An example how to do it:

cargo xtask build-documentation --packages=esp-wifi --chips=esp32c6
open docs/esp-wifi/0.9.1/esp32c6/esp_wifi/index.html