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SubjectRe: Ktimer / -rt9 (+custom) monotonic_clock going backwards.

* Steven Rostedt <rostedt@goodmis.org> wrote:

> static inline nsec_t __get_nsec_offset(void)
> {
> cycle_t cycle_now, cycle_delta;
> nsec_t ns_offset;
>
> /* read clocksource */
> cycle_now = read_clocksource(clock);
>
> /* calculate the delta since the last timeofday_periodic_hook */
> cycle_delta = (cycle_now - cycle_last) & clock->mask;
>
> /* convert to nanoseconds */
> ns_offset = cyc2ns(clock, ntp_adj, cycle_delta);
>
> /* Special case for jiffies tick/offset based systems
> * add arch specific offset
> */
> ns_offset += arch_getoffset();
>
> return ns_offset;
> }
>
> cycle_now is 32 bits. If the clocksource overflows (which it can in
> 30 seconds) the cyclec_delta will be wrong.

isnt cycle_t 64 bits?

Ingo
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