"Soft" limit on file descriptors that a single process can have open. A process might adjust its file descriptor limit to any value up to the "hard" limit defined by rlim_fd_max by using the setrlimit() call or issuing the limit command in whatever shell it is running. You do not require superuser privilege to adjust the limit to any value less than or equal to the hard limit.
1 to MAXINT
No. Loaded into rlimits structure.
Compared to rlim_fd_max and if rlim_fd_cur is greater than rlim_fd_max, rlim_fd_cur is reset to rlim_fd_max.
When the default number of open files for a process is not enough. Increasing this value means only that it is possibly not necessary for a program to use setrlimit(2) to increase the maximum number of file descriptors available to it.
Specify the amount of kernel pageable memory available. This memory is used primarily for kernel thread stacks. Increasing this number allows either larger stacks for the same number of threads or more threads. This parameter can only be set on 64–bit kernels. 64-bit kernels use a default stack size of 24 Kbytes.
64–bit kernels, 2 Gbytes
32–bit kernels, 512 Mbytes
64–bit kernels, 512 Mbytes - 24 Gbytes
32-bit kernels, 512 Mbytes
Increase when more threads are desired.