On Fri, Nov 27, 2020 at 1:15 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > Oh, this is a red herring. It's "make" output being misleading, and it > just comes from the FORCE keyword. > > And no, those don't actually change the end result for me. .. and that red herring was what made me think that it always recompiles the 'conf' binary. But no, that's not what is going on. profiling shows that it does spend a lot of time in the compiler (which was the other thing that made me incorrectly think it was the conf program getting recompiled every time), but it looks like maybe it's simply the cc-option testing that causes that: 33.68% cc1plus 16.71% cc1 14.75% ld 11.36% conf 7.51% sh 7.21% as 3.01% gcc 2.44% make 0.58% mkdir 0.39% rm 0.33% gcc-version.sh 0.24% collect2 0.23% cat 0.22% grep 0.20% cc-can-link.sh Oh well, I clearly misread the problem. Maybe 1.5s is more reasonable than I really expected it to be. Linus