Re: [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o

[Jiri Slaby]

On 19. 07. 22, 11:15, Masahiro Yamada wrote:
> On Tue, Jul 19, 2022 at 5:41 PM Jiri Slaby <jslaby@xxxxxxx> wrote:
> > Until the link-vmlinux.sh split (cf. the commit below), the linker was
> > run with jobserver set in MAKEFLAGS. After the split, the command in
> > Makefile.vmlinux_o is not prefixed by "+" anymore, so this information
> > is lost.
> >
> > Restore it as linkers working in parallel (esp. the LTO ones) make a use
> > of it. In this case, it is gcc producing this warning otherwise:
> > lto-wrapper: warning: jobserver is not available: ‘--jobserver-auth=’ is not present in ‘MAKEFLAGS’
> >
> > Cc: Sedat Dilek <sedat.dilek@xxxxxxxxx>
> > Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
> > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> > Cc: Signed-off-by: Martin Liska <mliska@xxxxxxx>
> > Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
> > Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
> > ---
> >
> > Notes:
> >      [v2] only commit message updated
>
>
> Did you read my previous email?
>
> https://lore.kernel.org/linux-kbuild/CAK7LNAS46hrVh3FNiHHL8_Hqp85VgWnsHyjQ4t-TFH_H344NOg@xxxxxxxxxxxxxx/

Huh, I neither received this email nor the linked one to my inbox. 
@suse.cz somehow filters mails from you :/. Let me figure out (and use 
kernel.org account for now). (And get back to your comments too.)

> >   scripts/Makefile.vmlinux_o | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
> > index 84019814f33f..886db0659d9c 100644
> > --- a/scripts/Makefile.vmlinux_o
> > +++ b/scripts/Makefile.vmlinux_o
> > @@ -65,7 +65,7 @@ define rule_ld_vmlinux.o
> >   endef
> >
> >   vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
> > -       $(call if_changed_rule,ld_vmlinux.o)
> > +       +$(call if_changed_rule,ld_vmlinux.o)
> >
> >   targets += vmlinux.o
> >
> > --
> > 2.37.1

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