Traditionally, the MINIX kernel and other kernel used a periodic timer for each CPU. This scheme suffers from several issues including being periodic at a fixed rate, doing a lot of things during each interrupt, polluting the callout data structures with a lot of unnecessary callouts which either do not fire or get rearmed frequently. Making the kernel tickless has several advantages, the most prominent being more efficient CPU usage because of less clock cycles being wasted in servicing periodic timer interrupts even when there is no callout to expire at that instant. Consequently, the processor can stay quiescent for longer durations and only be woken up if there is an actual timer to be expired, resulting in lesser power consumption.