Messages in this thread | | | Date | Fri, 23 Jan 2015 15:28:25 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 06/12] time: Add infrastructure to cap clocksource reads to the max_cycles value |
| |
On Thu, Jan 22, 2015 at 04:09:21PM -0800, John Stultz wrote: > +static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) > +{ > + cycle_t cycle_now, delta; > + > + /* read clocksource */ > + cycle_now = tkr->read(tkr->clock); > + > + /* calculate the delta since the last update_wall_time */ > + delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask); > + > + /* Cap delta value to the max_cycles values to avoid mult overflows */ > + if (unlikely(delta > tkr->clock->max_cycles)) > + delta = tkr->clock->max_cycles;
Should we not raise _something_ here? I know we cannot printk() here, but bad (TM) things happened if this ever triggers.
> + > + return delta; > +}
| |