On Tue, May 7, 2024 at 8:16 PM Nicolas Schier <nicolas@xxxxxxxxx> wrote: > > On Sun, Apr 28, 2024 at 12:32:53AM +0900, Masahiro Yamada wrote: > > Currently, Kbuild produces inconsistent results in some cases. > > > > You can do an interesting experiment using the --shuffle option, which > > is supported by GNU Make 4.4 or later. > > > > Set CONFIG_KVM_INTEL=y and CONFIG_KVM_AMD=m (or vice versa), and repeat > > incremental builds w/wo --shuffle=reverse. > > > > $ make > > [ snip ] > > CC arch/x86/kvm/kvm-asm-offsets.s > > > > $ make --shuffle=reverse > > [ snip ] > > CC [M] arch/x86/kvm/kvm-asm-offsets.s > > > > $ make > > [ snip ] > > CC arch/x86/kvm/kvm-asm-offsets.s > > > > arch/x86/kvm/kvm-asm-offsets.s is rebuilt every time w/wo the [M] marker. > > > > arch/x86/kvm/kvm-asm-offsets.s is built as built-in when it is built as > > a prerequisite of arch/x86/kvm/kvm-intel.o, which is built-in. > > > > arch/x86/kvm/kvm-asm-offsets.s is built as modular when it is built as > > a prerequisite of arch/x86/kvm/kvm-amd.o, which is a module. > > > > Another odd example is single target builds. > > > > When CONFIG_LKDTM=m, drivers/misc/lkdtm/rodata.o can be built as > > built-in or modular, depending on how it is built. > > > > $ make drivers/misc/lkdtm/lkdtm.o > > [ snip ] > > CC [M] drivers/misc/lkdtm/rodata.o > > > > $ make drivers/misc/lkdtm/rodata.o > > [ snip ] > > CC drivers/misc/lkdtm/rodata.o > > > > drivers/misc/lkdtm/rodata.o is built as modular when it is built as a > > prerequisite of another, but built as built-in when it is a final > > target. > > > > The same thing happens to drivers/memory/emif-asm-offsets.s when > > CONFIG_TI_EMIF_SRAM=m. > > > > $ make drivers/memory/ti-emif-sram.o > > [ snip ] > > CC [M] drivers/memory/emif-asm-offsets.s > > > > $ make drivers/memory/emif-asm-offsets.s > > [ snip ] > > CC drivers/memory/emif-asm-offsets.s > > > > This is because the part-of-module=y flag defined for the modules is > > inherited by its prerequisites. > > > > Target-specific variables are likely intended only for local use. > > This commit adds 'private' to them. > > > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > > --- > > uh, thanks for fixing this! (And for the bug documentation, as always!) > > I have just one question below. > > > > > Makefile | 8 ++++---- > > scripts/Makefile.build | 6 +++--- > > 2 files changed, 7 insertions(+), 7 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index 62557fabfee5..25dcc7ead330 100644 > > --- a/Makefile > > +++ b/Makefile > [...] > > @@ -1500,7 +1500,7 @@ MRPROPER_FILES += include/config include/generated \ > > > > # clean - Delete most, but leave enough to build external modules > > # > > -clean: rm-files := $(CLEAN_FILES) > > +clean: private rm-files := $(CLEAN_FILES) > > Did you leave 'clean: rm-files := $(KBUILD_EXTMOD)/...' for oot kmods > the way it is (w/o 'private') by intention? No. I missed to update this line. I will fix it up for consistency. Thanks. > > Even though I cannot think of a possible problem without the 'private', > I think it makes sense to change the line as well. > > W/ or w/o the 'clean'-update for oot kmods: > > Reviewed-by: Nicolas Schier <n.schier@xxxxxx> > > Kind regards, > Nicolas -- Best Regards Masahiro Yamada
