Limited Number of User (child) Processes on Cygwin 3.5 64x

Question

I've been using Cygwin 3.5.0-1.x86_64 under Windows 10, and having a hard time with the system limit on number of children a process can have. My maximum user processes seems to be only 256, which seems very low:

I thought this was a limitation from Cygwin, but after reading their update history page it seems that this value was changed in Cygwin 3.2, and the new limit number for child processes has increased to ~5000 and ~1200 for 64x and 32x bit systems. This implementation was removed on recent versions? Is there a way I can increase the maximum user processes limit?

Answer 1

Although I'm still not able to increase the limit of max user per processes, I figured it out my problem was being caused by OpenMPI compiler rather than Cygwin system limitation. It seems that many packages upgrades over the same setup might cause displacement of some dll, which leads to OpenMPI malfunction and system limit on number of children processes error.

I was able to correct it by performing a system rebase.