Hello Maciej, On Wednesday, April 9, 2008 at 21:19:55 +0100, Maciej W. Rozycki wrote:
> on some Linux platforms that use the RTC periodic interrupt as the > source of the system timer interrupt. Updating the RTC causes a > considerable disruption of the interrupt I guess this problem is due to the reset of the RTC oscillator, right? Then a solution could be to use an alternative method to set the RTC, not using reset, but holding the clock during a fraction of second, until ticks are in sync. Deliciously hackish, and surely illegal. Instead of normal: -1) wait for the next real half second -2) freeze clock -3) reset oscillator -4) write time -5) release clock -6) release oscillator Alternatively do: -1) wait for an RTC tick -2) freeze clock -3) write time + 1 second -4) wait for the next real second -5) release clock This holds the clock for up to a second, producing no more update nor alarm interrupts. But the oscillator still oscillates, so periodic interrupts should be undisturbed, during and after this procedure. Interrupts have to be enabled during step #4 of course. I'm not aware of any tool using this method. What are those PIE-timer platforms? Do you have one? Serge. -- Serge point Bets arobase laposte point net _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
