On 11/01/2021 02:06, Chaitanya Kulkarni wrote: > On 1/9/21 13:29, Pavel Begunkov wrote: >> On 09/01/2021 20:52, Chaitanya Kulkarni wrote: >>> On 1/9/21 12:40, Pavel Begunkov wrote: >>>> I expect you won't find any, but such little things can pile up >>>> into a not-easy-to-spot overhead over time. >>> That is what I suspected with the resulting assembly. The commit log >>> needs to document that there is no direct impact on the performance >> It's obvious that 3-4 extra mov $0 off(%reg) won't change performance >> but still hasn't been formally confirmed ... > This is obvious for you and me since we spent time into looking into > resulting assembly not every reviewer is expected to do that see [1]. >> >>> which can be seen with this patch, but this is nice to have >> ... so if you don't mind, I won't be resending just for that. > As per commit log guidelines [1] you have to quantify the optimization. > > Since you cannot quantify the optimization modify the commit log explaining And then you see "Optimizations usually aren’t free but trade-offs between", and the patch doesn't fall under it. Let me be frank, I see it more like as a whim. If the maintainer agrees with that strange requirement of yours and want to bury it under bureaucracy, fine by me, don't take it, I don't care, but I haven't ever been asked here to do that for patches as this. > that there is not significant performance benefit observe. It's not "I cannot" but rather "I haven't even tried to and expect...". Don't mix, there is a huge difference between. -- Pavel Begunkov
