Re: [GIT PULL] asm-generic updates for 6.11

["Arnd Bergmann" <arnd@arndb.de>]

On Wed, Jul 17, 2024, at 08:41, Johan Hovold wrote:
> On Wed, Jul 17, 2024 at 08:01:43AM +0200, Arnd Bergmann wrote:
>> On Wed, Jul 17, 2024, at 07:08, Linus Torvalds wrote:
>> > On Tue, 16 Jul 2024 at 21:57, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>> >>
>> >> Note, it really might be just 'allmodconfig'. We've had things that
>> >> depend on config entries in the past, eg the whole
>> >> CONFIG_HEADERS_INSTALL etc could affect things.
>> 
>> I had tried a partial allmodconfig build earlier to save time,
>> did a full build again now, still nothing:
>
> FWIW, I noticed this last Friday as well when I did a few builds of
> linux-next and every change I made triggered what appeared to be a full
> rebuild of the tree.
>
> This was with a trimmed config [1] and separate build tree (tmpfs).

Thanks, that makes it quicker to try out. I'm now using
your config to do more testing. I still don't see it with
a normal build though.

I do see that setting the timestamp of syscall.tbl to
a future date does result in always rebuilding everything,
but I don't think that is what you are seeing, since that
also produces a warning from make:

arnd@studio:~/arm-soc/build/bisect$ touch -t 202501010000 arch/x86/entry/syscalls/syscall_64.tbl 
arnd@studio:~/arm-soc/build/bisect$ make ARCH=x86 CROSS_COMPILE=x86_64-linux- 
make[2]: Warning: File 'arch/x86/entry/syscalls/syscall_64.tbl' has modification time 14483017 s in the future
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_64.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_x32.h
  SYSHDR  arch/x86/include/generated/asm/unistd_64_x32.h
  SYSTBL  arch/x86/include/generated/asm/syscalls_64.h
make[2]: warning:  Clock skew detected.  Your build may be incomplete.

     Arnd