| Message ID | 20240717124253.2275084-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kbuild: mark "FORCE" target as secondary | expand |
On Wed, Jul 17, 2024 at 9:43 PM Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > Starting with make-4.4.1, Kbuild uses the special .NOTINTERMEDIATE > target to mark all targets as not intermediate, which slightly changes > the behavior compared to older versions of make. > > This causes a build regression with my change to the system call table > scripts now in scripts/Makefile.asm-headers, forcing a rebuild of the > generated files with every make invocation and effectively breaking > incremental builds. > > I have narrowed down the change in behavior to the way that the > 'FORCE' target is treated: If this is marked as not intermediate, > the $(if_changed) macro always evaluates it as a missing prerequisite, > but if it is marked as .SECONDARY, it works like before. > > Cc: Masahiro Yamada <masahiroy@kernel.org> > Cc: linux-kbuild@vger.kernel.org > Fixes: 875ef1a57f32 ("kbuild: use .NOTINTERMEDIATE for future GNU Make versions") > Fixes: fbb5c0606fa4 ("kbuild: add syscall table generation to scripts/Makefile.asm-headers") > Closes: https://lore.kernel.org/lkml/91b10591-1554-4860-8843-01c6cfd7de13@app.fastmail.com/T/#m4c979c42d0c086f616e41b4ca76f2873902b8a25 > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > ---- > I'm still a bit confused by the way this works in detail, hopefully > Masahiro Yamada can either confirm that this is a correct fix or provide > a better one. Of course, NACK. Now I am surprised that this broken series was quickly merged into the mainline. I really dislike how you changed scripts/Makefile.asm-headers I will send a correct fix. Please do not break Kbuild even further. > --- > scripts/Kbuild.include | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include > index faf37bafa3f8..aa1ffaeb8fc0 100644 > --- a/scripts/Kbuild.include > +++ b/scripts/Kbuild.include > @@ -267,6 +267,7 @@ endif > # deleted files. > ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),) > .NOTINTERMEDIATE: > +.SECONDARY: FORCE > else > .SECONDARY: > endif > -- > 2.39.2 > >
On Wed, Jul 17, 2024, at 17:18, Masahiro Yamada wrote: > > Of course, NACK. > > Now I am surprised that this broken series was quickly merged > into the mainline. > I really dislike how you changed scripts/Makefile.asm-headers > > > I will send a correct fix. > Please do not break Kbuild even further. Should we maybe revert ff96f5c6971c..3db80c999deb then and find a better way to do it in 6.12? Arnd
On Thu, Jul 18, 2024 at 1:25 AM Arnd Bergmann <arnd@arndb.de> wrote: > > On Wed, Jul 17, 2024, at 17:18, Masahiro Yamada wrote: > > > > Of course, NACK. > > > > Now I am surprised that this broken series was quickly merged > > into the mainline. > > I really dislike how you changed scripts/Makefile.asm-headers > > > > > > I will send a correct fix. > > Please do not break Kbuild even further. > > Should we maybe revert ff96f5c6971c..3db80c999deb then > and find a better way to do it in 6.12? > > Arnd > > I do not think so. I pretty much like 4fe53bf2ba0a45cd708dcd4c3e8e1950731b3d4d, and I believe generating all syscall headers from a table is the right thing to do. So, it must happen. Currently, the new syscall-y syntax can be used only for architectures using the generic syscall table. I wonder what we should do for the other legacy architectures. Some years ago, I tried to unify 'archheaders' and 'asm-generic' into a more generic rule, but I did not find a nice solution, so I did not do anything. I need to find some way when I have time. For the rebuild problem, I think this should work: https://lore.kernel.org/all/20240717162421.1402773-1-masahiroy@kernel.org/T/#u (I only compile-tested arch64 and riscv, but the other architectires should be the same pattern.) -- Best Regards Masahiro Yamada
On Wed, Jul 17, 2024, at 18:45, Masahiro Yamada wrote: >> On Wed, Jul 17, 2024, at 17:18, Masahiro Yamada wrote: >> >> Should we maybe revert ff96f5c6971c..3db80c999deb then >> and find a better way to do it in 6.12? > > I do not think so. > > I pretty much like 4fe53bf2ba0a45cd708dcd4c3e8e1950731b3d4d, > and I believe generating all syscall headers from a table > is the right thing to do. > So, it must happen. Right, I meant to leave that part here and just revert the Makefile changes until we have something that has seen enough testing. > Currently, the new syscall-y syntax can be used only for > architectures using the generic syscall table. > I wonder what we should do for the other legacy architectures. I have patches for all architectures at https://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git/log/?h=syscall-tbl-6.11&id=92499ba526eac435 but I stopped after the ones using the generic syscall table since I had spent more time making sure the actual table contents are unchanged. > For the rebuild problem, I think this should work: > https://lore.kernel.org/all/20240717162421.1402773-1-masahiroy@kernel.org/T/#u > > (I only compile-tested arch64 and riscv, but the other architectires > should be the same pattern.) Right, I completely missed the "existing-targets" bit, and without that I couldn't figure out the rest correctly. I have checked this on the other architectures now and tried out the bit with the changed command line I got wrong. Sorry for causing these problems and thanks a lot for the fix! Arnd
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index faf37bafa3f8..aa1ffaeb8fc0 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -267,6 +267,7 @@ endif # deleted files. ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),) .NOTINTERMEDIATE: +.SECONDARY: FORCE else .SECONDARY: endif