What is the maximum number of threads in Linux?

Linux doesn’t have a separate threads per process limit, but has a limit on the total number of processes on the system (as threads just processes with a shared address space on Linux). This thread limit for linux can be modified at runtime by writing desired limit to /proc/sys/kernel/threads-max.

Is there a limit to number of threads?

Creating threads gets slower

For the 32-bit JVM, the stack size appears to limit the number of threads you can create. This may be due to the limited address space. In any case, the memory used by each thread’s stack add up. If you have a stack of 128KB and you have 20K threads it will use 2.5 GB of virtual memory.