[klabb3]

> once you do SO_RCVBUF the auto-tuning is out of the picture for that socket

Oh I didn’t realize this. That explains the switch in limits. However:

I would have liked to keep auto-tuning, but only change the max buffer size. It’s still weird to me that these are different modes with different limits and whatnot. In my case, I was parallelizing tcp and capping the max size would have been better, and instead varying the number of conns.

I gave up on it. Especially since I need cross platform user-space only, I don’t want to fiddle with these APIs that are all different and unpredictable. I guess it’s for the best anyway, to avoid as much per-platform hacks as possible.

> It's pretty clearly documented @ Documentation/networking/ip-sysctl.rst

I guess I need to step up my doc grepping game, cause it was quite hard to even find this on Google. I ran my own experiments to verify.

> Edit: downvotes, really? smh

Fwiw not me.