On Tue, Jul 14, 2020 at 11:13:26AM +0200, Thomas Gleixner wrote: > Frederic Weisbecker <[email protected]> writes: > > static inline unsigned calc_index(unsigned expires, unsigned lvl) > > { > > + /* > > + * Time may have past since the clock last reached an index of > > + * this @lvl. And that time, below LVL_GRAN(@lvl), is going to > > + * be substracted from the delta until we reach @expires. To > > + * fix that we must add one level granularity unit to make sure > > + * we rather expire late than early. Prefer ceil over floor. > > This comment confuses the hell out of me.
Me too... > > /* > * The timer wheel has to guarantee that a timer does not fire > * early. Early expiry can happen due to: > * - Timer is armed at the edge of a tick > * - Truncation of the expiry time in the outer wheel levels > * > * Round up with level granularity to prevent this. > */ > > Hmm? That's relieving, I'm updating the patch. Thanks!
