On Tue, 16 Jul 2024 at 17:53, Nathan Chancellor <nat...@kernel.org> wrote:
>
> Can confirm. I tried it initially and it did not seem to work but I
> think I may have been using the wrong object folder or something.
I wonder if our dependency rules might not be confused by a new header
file just showing up earlier in the search path.
So what might have happened for you is that it generated that new
arch/um/include/generated/runtime-const.h
file thanks to the Kbuild rule, but then it didn't actually re-build
the fs/dcache.o file, because the way our auto-dependency works is
that it generates that list of all the other files it depends on, and
it also depends on the exact build flags - but that would all miss the
case of "there's a new file in the include path".
So that would explain your "it did not seem to work".
There's some handwaving here, but I do think that this is a case that
our otherwise pretty good automatic dependency rules may fail at.
Linus
