The Plastic SCM server is a long-running memory-intensive process and we need to increase the default 'max_map_count' to avoid memory issues in the Mono framework code.
From the Linux Kernel documentation:
This file contains the maximum number of memory map areas a process may have. Memory map areas are used as a side-effect of calling malloc, directly by mmap and mprotect, and also when loading shared libraries.
While most applications need less than a thousand maps, certain programs, particularly malloc debuggers, may consume lots of them, e.g., up to one or two maps per allocation.
The default value is 65536.
The problem with using the 'max_map_count' default value is the risk of having a SIGSEGV error and a Plastic SCM server crash. We suggest that you to change this value to something bigger; something like 1000000 or higher removes the risk of mem issues.
You can easily set a new 'max_map_count' value using the following command:
sudo sysctl vm.max_map_count=1000000