High-resolution timers
Timer resolution is important if you have precise timing requirements, which is typical for real-time applications. The default timer in Linux is a clock that runs at a configurable rate, typically 100 Hz for embedded systems and 250 Hz for servers and desktops. The interval between two timer ticks is known as a jiffy and, in the examples given previously, is 10 milliseconds on an embedded SoC and 4 milliseconds on a server.
Linux gained more accurate timers from the real-time kernel project in version 2.6.18, and now they are available on all platforms, provided that there is a high-resolution timer source and device driver for it—which is almost always the case. You need to configure the kernel with CONFIG_HIGH_RES_TIMERS=y.
With this enabled, all the kernel and user space clocks will be accurate down to the granularity of the underlying hardware. Finding the actual clock granularity is difficult. The obvious answer is the value provided by clock_getres...
