On 07/01/2016 01:36 PM, Daniel Lezcano wrote: > On 06/30/2016 05:37 PM, Nicolas Pitre wrote: >> On Thu, 30 Jun 2016, Daniel Lezcano wrote: >>> + } >>>> +} >>> >>> >>> What bothers me with this division is the benefit of adding an extra >>> ultra >>> optimized division by 1000 in cpuidle.h while we have already >>> ktime_divns >>> which is optimized in ktime.h. >> >> It is "optimized" but still much heavier than what is presented above as >> it provides maximum precision. >> >> It all depends on how important the performance gain from the original >> shift by 10 was in the first place. > > Actually the original shift was there because it was convenient as a > simple ~div1000 operation. But against all odds, the approximation > introduced a regression on a very specific use case on PowerPC. > > We are not in the hot path and I think we can live with a ktime_divns > without problem. That would simplify the fix I believe. >
I agree too. I'll post next version with this. Thanks, Shreyas _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev