* [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o
@ 2022-07-19 8:41 Jiri Slaby
2022-07-19 8:41 ` [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking Jiri Slaby
2022-07-19 9:15 ` [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Masahiro Yamada
0 siblings, 2 replies; 7+ messages in thread
From: Jiri Slaby @ 2022-07-19 8:41 UTC (permalink / raw)
To: masahiroy
Cc: linux-kbuild, linux-kernel, Jiri Slaby, Sedat Dilek,
Michal Marek, Nick Desaulniers, Signed-off-by : Martin Liska
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
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
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking
2022-07-19 8:41 [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Jiri Slaby
@ 2022-07-19 8:41 ` Jiri Slaby
2022-07-19 9:15 ` Masahiro Yamada
2022-07-19 9:15 ` [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Masahiro Yamada
1 sibling, 1 reply; 7+ messages in thread
From: Jiri Slaby @ 2022-07-19 8:41 UTC (permalink / raw)
To: masahiroy
Cc: linux-kbuild, linux-kernel, Martin Liska, Sedat Dilek,
Michal Marek, Nick Desaulniers, Jiri Slaby
From: Martin Liska <mliska@suse.cz>
Prefix command in makefile run in order to preserve access to jobserver.
This is needed for gcc at least.
Fixes this warning:
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>
Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
Signed-off-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
Notes:
[v2] this is new in v2
scripts/Makefile.build | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index bb63374fb055..493f3c4e8461 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -247,8 +247,8 @@ endef
# Built-in and composite module parts
$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
- $(call if_changed_rule,cc_o_c)
- $(call cmd,force_checksrc)
+ +$(call if_changed_rule,cc_o_c)
+ +$(call cmd,force_checksrc)
# To make this rule robust against "Argument list too long" error,
# ensure to add $(obj)/ prefix by a shell command.
@@ -457,7 +457,7 @@ endef
$(multi-obj-m): objtool-enabled := $(delay-objtool)
$(multi-obj-m): part-of-module := y
$(multi-obj-m): %.o: %.mod FORCE
- $(call if_changed_rule,ld_multi_m)
+ +$(call if_changed_rule,ld_multi_m)
$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
targets := $(filter-out $(PHONY), $(targets))
--
2.37.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking
2022-07-19 8:41 ` [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking Jiri Slaby
@ 2022-07-19 9:15 ` Masahiro Yamada
2022-09-20 8:06 ` Jiri Slaby
0 siblings, 1 reply; 7+ messages in thread
From: Masahiro Yamada @ 2022-07-19 9:15 UTC (permalink / raw)
To: Jiri Slaby
Cc: Linux Kbuild mailing list, Linux Kernel Mailing List,
Martin Liska, Sedat Dilek, Michal Marek, Nick Desaulniers
On Tue, Jul 19, 2022 at 5:41 PM Jiri Slaby <jslaby@suse.cz> wrote:
>
> From: Martin Liska <mliska@suse.cz>
>
> Prefix command in makefile run in order to preserve access to jobserver.
> This is needed for gcc at least.
>
> Fixes this warning:
> lto-wrapper: warning: jobserver is not available: ‘--jobserver-auth=’ is not present in ‘MAKEFLAGS’
What is lto-wrapper ?
>
> 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>
> Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
> Signed-off-by: Martin Liska <mliska@suse.cz>
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> ---
>
> Notes:
> [v2] this is new in v2
>
> scripts/Makefile.build | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index bb63374fb055..493f3c4e8461 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -247,8 +247,8 @@ endef
>
> # Built-in and composite module parts
> $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
> - $(call if_changed_rule,cc_o_c)
> - $(call cmd,force_checksrc)
> + +$(call if_changed_rule,cc_o_c)
> + +$(call cmd,force_checksrc)
cmd_force_checksrc invokes sparse.
How is it related to GCC?
>
> # To make this rule robust against "Argument list too long" error,
> # ensure to add $(obj)/ prefix by a shell command.
> @@ -457,7 +457,7 @@ endef
> $(multi-obj-m): objtool-enabled := $(delay-objtool)
> $(multi-obj-m): part-of-module := y
> $(multi-obj-m): %.o: %.mod FORCE
> - $(call if_changed_rule,ld_multi_m)
> + +$(call if_changed_rule,ld_multi_m)
> $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
cmd_ld_multi_m invokes $(LD) directly.
How is it related to gcc?
>
> targets := $(filter-out $(PHONY), $(targets))
> --
> 2.37.1
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking
2022-07-19 9:15 ` Masahiro Yamada
@ 2022-09-20 8:06 ` Jiri Slaby
2022-09-20 12:34 ` Martin Liška
0 siblings, 1 reply; 7+ messages in thread
From: Jiri Slaby @ 2022-09-20 8:06 UTC (permalink / raw)
To: Masahiro Yamada
Cc: Linux Kbuild mailing list, Linux Kernel Mailing List,
Martin Liska, Sedat Dilek, Michal Marek, Nick Desaulniers
On 19. 07. 22, 11:15, Masahiro Yamada wrote:
> On Tue, Jul 19, 2022 at 5:41 PM Jiri Slaby <jslaby@suse.cz> wrote:
>>
>> From: Martin Liska <mliska@suse.cz>
>>
>> Prefix command in makefile run in order to preserve access to jobserver.
>> This is needed for gcc at least.
>>
>> Fixes this warning:
>> lto-wrapper: warning: jobserver is not available: ‘--jobserver-auth=’ is not present in ‘MAKEFLAGS’
>
>
> What is lto-wrapper ?
lto-wrapper is a part of gcc:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/lto-wrapper.cc
And is invoked during the link of LTO objects (also to link in parallel
if jobserver is available).
I am leaving the unanswered questions below for Martin to answer.
>> 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>
>> Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
>> Signed-off-by: Martin Liska <mliska@suse.cz>
>> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
>> ---
>>
>> Notes:
>> [v2] this is new in v2
>>
>> scripts/Makefile.build | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
>> index bb63374fb055..493f3c4e8461 100644
>> --- a/scripts/Makefile.build
>> +++ b/scripts/Makefile.build
>> @@ -247,8 +247,8 @@ endef
>>
>> # Built-in and composite module parts
>> $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
>> - $(call if_changed_rule,cc_o_c)
>> - $(call cmd,force_checksrc)
>> + +$(call if_changed_rule,cc_o_c)
>> + +$(call cmd,force_checksrc)
>
>
> cmd_force_checksrc invokes sparse.
> How is it related to GCC?
>
>
>
>
>>
>> # To make this rule robust against "Argument list too long" error,
>> # ensure to add $(obj)/ prefix by a shell command.
>> @@ -457,7 +457,7 @@ endef
>> $(multi-obj-m): objtool-enabled := $(delay-objtool)
>> $(multi-obj-m): part-of-module := y
>> $(multi-obj-m): %.o: %.mod FORCE
>> - $(call if_changed_rule,ld_multi_m)
>> + +$(call if_changed_rule,ld_multi_m)
>> $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
>
>
> cmd_ld_multi_m invokes $(LD) directly.
> How is it related to gcc?
--
js
suse labs
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking
2022-09-20 8:06 ` Jiri Slaby
@ 2022-09-20 12:34 ` Martin Liška
0 siblings, 0 replies; 7+ messages in thread
From: Martin Liška @ 2022-09-20 12:34 UTC (permalink / raw)
To: Jiri Slaby, Masahiro Yamada
Cc: Linux Kbuild mailing list, Linux Kernel Mailing List,
Sedat Dilek, Michal Marek, Nick Desaulniers
On 9/20/22 10:06, Jiri Slaby wrote:
> On 19. 07. 22, 11:15, Masahiro Yamada wrote:
>> On Tue, Jul 19, 2022 at 5:41 PM Jiri Slaby <jslaby@suse.cz> wrote:
>>>
>>> From: Martin Liska <mliska@suse.cz>
>>>
>>> Prefix command in makefile run in order to preserve access to jobserver.
>>> This is needed for gcc at least.
>>>
>>> Fixes this warning:
>>> lto-wrapper: warning: jobserver is not available: ‘--jobserver-auth=’ is not present in ‘MAKEFLAGS’
>>
>>
>> What is lto-wrapper ?
>
> lto-wrapper is a part of gcc:
> https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/lto-wrapper.cc
>
> And is invoked during the link of LTO objects (also to link in parallel if jobserver is available).
Yes, it's a driver that is invoked by Linker when it decides to use LTO mode in GCC compiler.
Later on the lto-wrapper connects to make's jobserver and runs in parallel. Note a recent [1]
make implemented named pipes when it comes to communication with jobserver. And thus the '+'
won't be needed in the future, but we need it for now.
Cheers,
Martin
[1] https://git.savannah.gnu.org/cgit/make.git/commit/?id=7ad2593b2d2bb5b9332f4444d8bf93ac6f958bc6
>
> I am leaving the unanswered questions below for Martin to answer.
>
>>> 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>
>>> Fixes: 5d45950dfbb1 (kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o)
>>> Signed-off-by: Martin Liska <mliska@suse.cz>
>>> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
>>> ---
>>>
>>> Notes:
>>> [v2] this is new in v2
>>>
>>> scripts/Makefile.build | 6 +++---
>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
>>> index bb63374fb055..493f3c4e8461 100644
>>> --- a/scripts/Makefile.build
>>> +++ b/scripts/Makefile.build
>>> @@ -247,8 +247,8 @@ endef
>>>
>>> # Built-in and composite module parts
>>> $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
>>> - $(call if_changed_rule,cc_o_c)
>>> - $(call cmd,force_checksrc)
>>> + +$(call if_changed_rule,cc_o_c)
>>> + +$(call cmd,force_checksrc)
>>
>>
>> cmd_force_checksrc invokes sparse.
>> How is it related to GCC?
>>
>>
>>
>>
>>>
>>> # To make this rule robust against "Argument list too long" error,
>>> # ensure to add $(obj)/ prefix by a shell command.
>>> @@ -457,7 +457,7 @@ endef
>>> $(multi-obj-m): objtool-enabled := $(delay-objtool)
>>> $(multi-obj-m): part-of-module := y
>>> $(multi-obj-m): %.o: %.mod FORCE
>>> - $(call if_changed_rule,ld_multi_m)
>>> + +$(call if_changed_rule,ld_multi_m)
>>> $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
>>
>>
>> cmd_ld_multi_m invokes $(LD) directly.
>> How is it related to gcc?
>
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o
2022-07-19 8:41 [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Jiri Slaby
2022-07-19 8:41 ` [PATCH v2 2/2] kbuild: lto: preserve MAKEFLAGS for module linking Jiri Slaby
@ 2022-07-19 9:15 ` Masahiro Yamada
2022-09-20 6:16 ` Jiri Slaby
1 sibling, 1 reply; 7+ messages in thread
From: Masahiro Yamada @ 2022-07-19 9:15 UTC (permalink / raw)
To: Jiri Slaby
Cc: Linux Kbuild mailing list, Linux Kernel Mailing List,
Sedat Dilek, Michal Marek, Nick Desaulniers,
Signed-off-by : Martin Liska
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/
>
> 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
>
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o
2022-07-19 9:15 ` [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Masahiro Yamada
@ 2022-09-20 6:16 ` Jiri Slaby
0 siblings, 0 replies; 7+ messages in thread
From: Jiri Slaby @ 2022-09-20 6:16 UTC (permalink / raw)
To: Masahiro Yamada, Jiri Slaby
Cc: Linux Kbuild mailing list, Linux Kernel Mailing List,
Sedat Dilek, Michal Marek, Nick Desaulniers,
Signed-off-by : Martin Liska
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
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-09-20 12:35 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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2022-07-19 9:15 ` Masahiro Yamada
2022-09-20 8:06 ` Jiri Slaby
2022-09-20 12:34 ` Martin Liška
2022-07-19 9:15 ` [PATCH v2 1/2] kbuild: pass jobserver to cmd_ld_vmlinux.o Masahiro Yamada
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