[pron]

Even 4k is a lot, and whatever memory is committed stays committed (and worse, it may even be paged). Perhaps it would be possible for the kernel to uncommit unused stack pages, but I don't think kernels want to assume threads never access memory below their stack pointer.

[garmaine]

Oh I agree OS threads a really heavyweight and there is a real need for fibers / green threads. I think we're arguing over whether they are 100x more efficient or 10,000x more efficient. Details matter ;) Thanks for your work on this for Java!

[lostmsu]

I think you severely overestimate the efficiency gain both times.

[garmaine]

It's a bit dated, but here's a reference:

https://blog.tsunanet.net/2010/11/how-long-does-it-take-to-m...