Re: [PATCH] sched: remove sched_find_first_bit()

From: Ingo Molnar
Date: Tue May 16 2017 - 04:30:56 EST



* Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> wrote:

> I collected about 700 results in dmesg, and took 600 fastest.
> For the vanilla kernel, the average value is 368, and for patched
> kernel it is 388. It's 5% slower. But the standard deviation is
> really big for both series' - 131 and 106 cycles respectively, which
> is ~ 30%. And so, my conclusion is: there's no benefit in using
> sched_find_first_bit() comparing to find_first_bit().

Erm, so you in essence claim:

"according to measurements the new code is 5% slower, with a high, 30%
stddev, hence the new code is better!"

Basic logic fail...

Thanks,

Ingo