On Fri, Jun 1, 2018 at 2:54 PM, Gautham R Shenoy <e...@linux.vnet.ibm.com> wrote: > Hi Balbir, > > Thanks for reviewing the patch! > > On Fri, Jun 01, 2018 at 12:51:05AM +1000, Balbir Singh wrote: >> On Thu, May 31, 2018 at 10:15 PM, Gautham R. Shenoy > > [..snip..] >> > >> > +static u64 get_snooze_timeout(struct cpuidle_device *dev, >> > + struct cpuidle_driver *drv, >> > + int index) >> > +{ >> > + int i; >> > + >> > + if (unlikely(!snooze_timeout_en)) >> > + return default_snooze_timeout; >> > + >> > + for (i = index + 1; i < drv->state_count; i++) { >> > + struct cpuidle_state *s = &drv->states[i]; >> > + struct cpuidle_state_usage *su = &dev->states_usage[i]; >> > + >> > + if (s->disabled || su->disable) >> > + continue; >> > + >> > + return s->target_residency * tb_ticks_per_usec; >> >> Can we ensure this is not prone to overflow? > > s->target_residency is an "unsigned int" so can take a maximum value > of UINT_MAX. tb_ticks_per_usec is an "unsigned long" with a value in > the range of 100-1000. The return value is a u64. The product of > s->target_residency and tb_ticks_per_usec should be contained in u64. >
Fair enough, looks reasonable to me Balbir Singh.