Chapter 5 of Daniel Bovet's "Understanding the Linux Kernel" mentions three clocks: Real Time Clocks (RTC), Time Stamp Counter (TSC) and Programmable Interval Timer (PIT). TSC and PIT work with similar approach as both of them set up when the system is booted. But why the PIT is used by kernel as TSC always come with an Intel x86 processor. Both TSC and PIT hold an incrementing counter which is retrievable through macro rdtscl or do_gettimeofday() and do_fast_gettimeoffset(), how the counter is properly set up initially so that it reflects current time? Thanks, -Hong - Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
