Understanding System Limits

Resources on a system tend to be finite (alas!), and some are more limited than others. This chapter describes some of the limits on a QNX Neutrino system.

Let's start by considering the limits on describing limits.

QNX Neutrino is a microkernel OS, so many things that might be a core limit in some operating systems instead depend on the particular manager that implements that service under QNX Neutrino, especially for filesystems, where there are multiple possible filesystems.

Many resources depend on how much memory is available. Other limits depend on your target system. For example, the virtual address space for a process can vary by processor; it's 2 GB on ARM, and 3.5 GB on x86.

Some limits are a complex interaction between many things. To quote the simple/obvious limit is misleading; describing all of the interactions can be complicated. The key thing to remember while reading this chapter is that there can be many factors behind a limit.