Hi, On Tuesday 02 January 2007 21:50, john stultz wrote:
> > > It should be called every NTP_INTERVAL_FREQ times, but occasionally > > > it's off > > Wait, so second_overflow should be called every NTP_INTERVAL_FREQ times > (instead of every second)? Surely that's not right. But it is, that's the reason the various adjustment values are divided by it, so they are applied to the next NTP_INTERVAL_FREQ times. BTW I think NTP_INTERVAL_FREQ isn't the right name, CLOCK_UPDATE_FREQ would be a better name, currently ntp is the main user, but a clock can also be updated via other means (e.g. adjtimex or another clock). > > > So in this case the loop in update_wall_time() should rather look like > > > this: > > > > > > while (offset >= clock->cycle_interval) { > > > ... > > > second_overflow(); > > > while (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) { > > > clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift; > > > xtime.tv_sec++; > > > } > > > ... > > > } > > > > > > (Also note the change from "if" to "while".) > > This would assume that clock->cycle_interval would *always* be the > length of a full second and that isn't what the patch trying to do. > > Maybe could you explain this some more? As I said this was the case for a value of one. Anyway, to avoid these problems, I'd prefer to keep it at least at 2 or better at 4. This would still drastically reduce the time spent in the loop and we can revisit the issue later. bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/