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

[Jiri Slaby <jirislaby@kernel.org>]

On 19. 07. 22, 11:15, Masahiro Yamada wrote:
> On Tue, Jul 19, 2022 at 5:41 PM Jiri Slaby <jslaby@suse.cz> 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@gmail.com>
>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>> Cc: Michal Marek <michal.lkml@markovi.net>
>> Cc: Nick Desaulniers <ndesaulniers@google.com>
>> Cc: Signed-off-by: Martin Liska <mliska@suse.cz>
>> Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
>> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
>> ---
>>
>> Notes:
>>      [v2] only commit message updated
> 
> 
> Did you read my previous email?
> 
> https://lore.kernel.org/linux-kbuild/CAK7LNAS46hrVh3FNiHHL8_Hqp85VgWnsHyjQ4t-TFH_H344NOg@mail.gmail.com/

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
>>
> 
> 

-- 
js