PIT_TICK_RATE      18 arch/x86/include/asm/mach_timer.h 	((PIT_TICK_RATE * CALIBRATE_TIME_MSEC + 1000/2)/1000)
PIT_TICK_RATE       8 arch/x86/include/asm/timex.h #define CLOCK_TICK_RATE		PIT_TICK_RATE
PIT_TICK_RATE      21 include/linux/i8253.h #define PIT_LATCH	((PIT_TICK_RATE + HZ/2) / HZ)