[PATCH iproute2] build: avoid make jobserver warnings

[PATCH iproute2] build: avoid make jobserver warnings

[Jan Engelhardt]

I observe:

	» make -j8 CCOPTS=-ggdb3
	lib
	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
	make[1]: Nothing to be done for 'all'.
	ip
	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
	    CC       ipntable.o

MFLAGS is a historic variable of some kind; removing it fixes the
jobserver issue.
---
 Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index cadda235..5b040415 100644
--- a/Makefile
+++ b/Makefile
@@ -63,7 +63,7 @@ LDLIBS += $(LIBNETLINK)
 all: config.mk
 	@set -e; \
 	for i in $(SUBDIRS); \
-	do echo; echo $$i; $(MAKE) $(MFLAGS) -C $$i; done
+	do echo; echo $$i; $(MAKE) -C $$i; done
 
 .PHONY: clean clobber distclean check cscope version
 
@@ -101,11 +101,11 @@ version:
 
 clean:
 	@for i in $(SUBDIRS) testsuite; \
-	do $(MAKE) $(MFLAGS) -C $$i clean; done
+	do $(MAKE) -C $$i clean; done
 
 clobber:
 	touch config.mk
-	$(MAKE) $(MFLAGS) clean
+	$(MAKE) clean
 	rm -f config.mk cscope.*
 
 distclean: clobber
-- 
2.28.0

Re: [PATCH iproute2] build: avoid make jobserver warnings

[Stephen Hemminger]

On Tue, 22 Sep 2020 01:22:31 +0200
Jan Engelhardt <jengelh@inai.de> wrote:

> I observe:
> 
> 	» make -j8 CCOPTS=-ggdb3
> 	lib
> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> 	make[1]: Nothing to be done for 'all'.
> 	ip
> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> 	    CC       ipntable.o
> 
> MFLAGS is a historic variable of some kind; removing it fixes the
> jobserver issue.

MFLAGS is a way to pass flags from original make into the sub-make.
Not sure if it is used anywhere else.

Re: [PATCH iproute2] build: avoid make jobserver warnings

[Jan Engelhardt]

On Tuesday 2020-09-22 02:19, Stephen Hemminger wrote:
>> I observe:
>> 
>> 	» make -j8 CCOPTS=-ggdb3
>> 	lib
>> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
>> 	make[1]: Nothing to be done for 'all'.
>> 	ip
>> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
>> 	    CC       ipntable.o
>> 
>> MFLAGS is a historic variable of some kind; removing it fixes the
>> jobserver issue.
>
>MFLAGS is a way to pass flags from original make into the sub-make.

MAKEFLAGS and MFLAGS are already exported by make (${MAKE} is magic
methinks), so they need no explicit passing. You can check this by
adding something like 'echo ${MAKEFLAGS}' to the lib/Makefile
libnetlink.a target and then invoking e.g. `make -r` from the
toplevel, and notice how -r shows up again in the submake.

Re: [PATCH iproute2] build: avoid make jobserver warnings

[Stephen Hemminger]

On Tue, 22 Sep 2020 08:15:59 +0200 (CEST)
Jan Engelhardt <jengelh@inai.de> wrote:

> On Tuesday 2020-09-22 02:19, Stephen Hemminger wrote:
> >> I observe:
> >> 
> >> 	» make -j8 CCOPTS=-ggdb3
> >> 	lib
> >> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> >> 	make[1]: Nothing to be done for 'all'.
> >> 	ip
> >> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> >> 	    CC       ipntable.o
> >> 
> >> MFLAGS is a historic variable of some kind; removing it fixes the
> >> jobserver issue.  
> >
> >MFLAGS is a way to pass flags from original make into the sub-make.  
> 
> MAKEFLAGS and MFLAGS are already exported by make (${MAKE} is magic
> methinks), so they need no explicit passing. You can check this by
> adding something like 'echo ${MAKEFLAGS}' to the lib/Makefile
> libnetlink.a target and then invoking e.g. `make -r` from the
> toplevel, and notice how -r shows up again in the submake.

For context:
https://www.gnu.org/software/make/manual/html_node/Options_002fRecursion.html

With your change does the options through the same?
My concern is that this change might break how distros do their package builds,
and cross compilation.

Re: [PATCH iproute2] build: avoid make jobserver warnings

[Jan Engelhardt]

On Thursday 2020-09-24 18:11, Stephen Hemminger wrote:
>> >
>> >MFLAGS is a way to pass flags from original make into the sub-make.  
>> 
>> MAKEFLAGS and MFLAGS are already exported by make (${MAKE} is magic
>> methinks), so they need no explicit passing. You can check this by
>> adding something like 'echo ${MAKEFLAGS}' to the lib/Makefile
>> libnetlink.a target and then invoking e.g. `make -r` from the
>> toplevel, and notice how -r shows up again in the submake.
>
>With your change does the options through the same?

Well yes.

Re: [PATCH iproute2] build: avoid make jobserver warnings

[Stephen Hemminger]

On Thu, 24 Sep 2020 18:56:33 +0200 (CEST)
Jan Engelhardt <jengelh@inai.de> wrote:

> On Thursday 2020-09-24 18:11, Stephen Hemminger wrote:
> >> >
> >> >MFLAGS is a way to pass flags from original make into the sub-make.    
> >> 
> >> MAKEFLAGS and MFLAGS are already exported by make (${MAKE} is magic
> >> methinks), so they need no explicit passing. You can check this by
> >> adding something like 'echo ${MAKEFLAGS}' to the lib/Makefile
> >> libnetlink.a target and then invoking e.g. `make -r` from the
> >> toplevel, and notice how -r shows up again in the submake.  
> >
> >With your change does the options through the same?  
> 
> Well yes.

Ok, tested a number of cases, and this works for all of them.

But, the patch is missing Signed-off-by which is required for iproute2.
Please resend with DCO.

Re: [iproute PATCH] build: avoid make jobserver warnings

[Stephen Hemminger]

On Mon, 28 Sep 2020 21:08:01 +0200
Jan Engelhardt <jengelh@inai.de> wrote:

> I observe:
> 
> 	» make -j8 CCOPTS=-ggdb3
> 	lib
> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> 	make[1]: Nothing to be done for 'all'.
> 	ip
> 	make[1]: warning: -j8 forced in submake: resetting jobserver mode.
> 	    CC       ipntable.o
> 
> MFLAGS is a historic variable of some kind; removing it fixes the
> jobserver issue.
> 
> Signed-off-by: Jan Engelhardt <jengelh@inai.de>

Applied.