On Tue, Jul 30, 2024, at 06:10, Linus Torvalds wrote: > > Of course, I never did any build timings. I'm not sure how much it > actually shows up on that level. A couple of bad cases won't be *that* > noticeable when most cases aren't too horrid. I did a little bit of build timing last week, which confirms exactly what you expect here: On individual files, the difference can easily be 1000x faster, like on that arch/x86/xen/setup.c file, but overall the difference in build speed for an allmodconfig or defconfig build was between 1% and 3%, depending on how many of the extreme cases are included. Of course, it would be easy to take one of the extreme cases and add another expansion that then drives the memory usage and/or compile time up to a point where the build fails. Arnd