[Buildroot] Qt5 parallel build of qmake

[Buildroot] Qt5 parallel build of qmake

[Arnout Vandecappelle]

 Hi all,

 I've put a few people in Cc that seem to be active users of Qt5.

 I noticed during a test build that during the configure step, qmake is built
but not in parallel. I think it should be possible to enable parallel build for
qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
someone be interested in checking that out?

 Ideally, you should also test with different make versions because they
sometimes throw other stuff in the MAKE variable which may screw things up.

 Regards,
 Arnout

[Buildroot] Qt5 parallel build of qmake

[Giulio Benetti]

Hi Arnout, All,

Il 18/04/2019 00:16, Arnout Vandecappelle ha scritto:
>   Hi all,
> 
>   I've put a few people in Cc that seem to be active users of Qt5.
> 
>   I noticed during a test build that during the configure step, qmake is built
> but not in parallel. I think it should be possible to enable parallel build for
> qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
> someone be interested in checking that out?

I am interested. I'll try to have it working, let's see if I'm able.

>   Ideally, you should also test with different make versions because they
> sometimes throw other stuff in the MAKE variable which may screw things up.

How much back should I go with make versions?
I mean, now I have 4.1, maybe back to 3.82?
Or more?

Best regards
-- 
Giulio Benetti
CTO

MICRONOVA SRL
Sede: Via A. Niedda 3 - 35010 Vigonza (PD)
Tel. 049/8931563 - Fax 049/8931346
Cod.Fiscale - P.IVA 02663420285
Capitale Sociale ? 26.000 i.v.
Iscritta al Reg. Imprese di Padova N. 02663420285
Numero R.E.A. 258642

>   Regards,
>   Arnout
> 

[Buildroot] Qt5 parallel build of qmake

[Arnout Vandecappelle]

On 18/04/2019 00:53, Giulio Benetti wrote:
> Hi Arnout, All,
> 
> Il 18/04/2019 00:16, Arnout Vandecappelle ha scritto:
>> ? Hi all,
>>
>> ? I've put a few people in Cc that seem to be active users of Qt5.
>>
>> ? I noticed during a test build that during the configure step, qmake is built
>> but not in parallel. I think it should be possible to enable parallel build for
>> qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
>> someone be interested in checking that out?
> 
> I am interested. I'll try to have it working, let's see if I'm able.
> 
>> ? Ideally, you should also test with different make versions because they
>> sometimes throw other stuff in the MAKE variable which may screw things up.
> 
> How much back should I go with make versions?
> I mean, now I have 4.1, maybe back to 3.82?
> Or more?

 Just 4.1 and 3.82 should be fine.

 Regards,
 Arnout

[Buildroot] Qt5 parallel build of qmake

[Giulio Benetti]

Hello Arnout, All,

Il 21/04/2019 09:08, Arnout Vandecappelle ha scritto:
> 
> 
> On 18/04/2019 00:53, Giulio Benetti wrote:
>> Hi Arnout, All,
>>
>> Il 18/04/2019 00:16, Arnout Vandecappelle ha scritto:
>>>  ? Hi all,
>>>
>>>  ? I've put a few people in Cc that seem to be active users of Qt5.
>>>
>>>  ? I noticed during a test build that during the configure step, qmake is built
>>> but not in parallel. I think it should be possible to enable parallel build for
>>> qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
>>> someone be interested in checking that out?

I've found out which is the problem and where is its origin.

On qt5base(and every other package using MAKEFLAGS) this:
MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
expands in this:
MAKEFLAGS=" --no-print-directory -- -j5"
so -j5 is ignored, then is not built in parallel.

In:
https://git.buildroot.net/buildroot/tree/support/scripts/mkmakefile#n33

basic Makefile is created with a dashed argument(-C to pass Buildroot 
Root Makefile as argument), but then also O=... option is passed.

Here is a snippet of my Makefile file created by mkmakefile script:
...
MAKEARGS := -C /home/giuliobenetti/git/buildroot
MAKEARGS += O=$(if $(patsubst /%,,$(makedir)),$(CURDIR)/)$(patsubst 
%/,%,$(makedir))

MAKEFLAGS += --no-print-directory

.PHONY: _all $(MAKECMDGOALS)

all	:= $(filter-out Makefile,$(MAKECMDGOALS))

_all:
	echo Root MAKEARGS=$(MAKEARGS)
	echo Root MAKEFLAGS=$(MAKEFLAGS)
	$(Q)umask 0022 && $(MAKE) $(MAKEARGS) $(all)
...

Doing lot of tries I've found out(I didn't know) that "make", when
evaluates $(MAKEARGS) it works as expected and gives:
Root MAKEARGS=-C /home/giuliobenetti/git/buildroot 
O=/home/giuliobenetti/git/build-br/.

BUT, when printing MAKEFLAGS with echo, it gives:
Root MAKEFLAGS= --no-print-directory --

qt5base and every other package using $(MAKEFLAGS) under a *recipe* only 
will always evaluate $(MAKEFLAGS) as "--".
Indeed if you try to use $(info $(MAKEFLAGS)) it will be different, 
without showing the 2 dashes.

Going deeper I've found that those 2 dashes are appended only if you 
pass to MAKEARGS some variable like "O=/home/..."
I mean, if you remove "O=/home/..." then MAKEFLAGS is 
"--no-print-directory" only.

The point is that MAKEARGS expects Makefile arguments only and not 
Variable as I understand. When you add variables, a "--" is appended 
between Make flags and Variables.

One possible solution I thought is cleaning MAKEFLAGS from those 
isolated 2 dashes.
Before I thought to pass directly O=/home/.. when calling $(MAKE),
but the problems comes out again, since in sub-makefile, that will be a 
MAKEARGS again.
I don't see any different way to deny Make to emit "--".

This impacts MAKEFLAGS variable everywhere when evaluated under recipe 
like "echo $(MAKEFLAGS)" and it works in this way for both make-4.1 and 
make-3.82 too.

What do you think?

Happy easter and kind regards!
-- 
Giulio Benetti
CTO

MICRONOVA SRL
Sede: Via A. Niedda 3 - 35010 Vigonza (PD)
Tel. 049/8931563 - Fax 049/8931346
Cod.Fiscale - P.IVA 02663420285
Capitale Sociale ? 26.000 i.v.
Iscritta al Reg. Imprese di Padova N. 02663420285
Numero R.E.A. 258642

>> I am interested. I'll try to have it working, let's see if I'm able.
>>
>>>  ? Ideally, you should also test with different make versions because they
>>> sometimes throw other stuff in the MAKE variable which may screw things up.
>>
>> How much back should I go with make versions?
>> I mean, now I have 4.1, maybe back to 3.82?
>> Or more?
> 
>   Just 4.1 and 3.82 should be fine.
> 
>   Regards,
>   Arnout
> 

[Buildroot] Qt5 parallel build of qmake

[Arnout Vandecappelle]

On 22/04/2019 00:43, Giulio Benetti wrote:
> Hello Arnout, All,
> 
> Il 21/04/2019 09:08, Arnout Vandecappelle ha scritto:
>>
>>
>> On 18/04/2019 00:53, Giulio Benetti wrote:
>>> Hi Arnout, All,
>>>
>>> Il 18/04/2019 00:16, Arnout Vandecappelle ha scritto:
>>>> ?? Hi all,
>>>>
>>>> ?? I've put a few people in Cc that seem to be active users of Qt5.
>>>>
>>>> ?? I noticed during a test build that during the configure step, qmake is built
>>>> but not in parallel. I think it should be possible to enable parallel build for
>>>> qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
>>>> someone be interested in checking that out?
> 
> I've found out which is the problem and where is its origin.
> 
> On qt5base(and every other package using MAKEFLAGS) this:
> MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
> expands in this:
> MAKEFLAGS=" --no-print-directory -- -j5"
> so -j5 is ignored, then is not built in parallel.
> 
> In:
> https://git.buildroot.net/buildroot/tree/support/scripts/mkmakefile#n33

 Note that I observed the same issue without out-of-tree build, and anyway if I
do out-of-tree build I always use explicit O= rather than the generated
makefile. So the problem is not (only) due to mkmakefile.

> 
> basic Makefile is created with a dashed argument(-C to pass Buildroot Root
> Makefile as argument), but then also O=... option is passed.
> 
> Here is a snippet of my Makefile file created by mkmakefile script:
> ...
> MAKEARGS := -C /home/giuliobenetti/git/buildroot
> MAKEARGS += O=$(if $(patsubst /%,,$(makedir)),$(CURDIR)/)$(patsubst
> %/,%,$(makedir))

 Note that MAKEARGS is not a special variable for make...

> 
> MAKEFLAGS += --no-print-directory

 But MAKEFLAGS is. However, the MAKEFLAGS variable is always rebuilt by the new
make process by combining the environment variable MAKEFLAGS with the command
line options that are passed to it.


> .PHONY: _all $(MAKECMDGOALS)
> 
> all??? := $(filter-out Makefile,$(MAKECMDGOALS))
> 
> _all:
> ????echo Root MAKEARGS=$(MAKEARGS)
> ????echo Root MAKEFLAGS=$(MAKEFLAGS)
> ????$(Q)umask 0022 && $(MAKE) $(MAKEARGS) $(all)
> ...
> 
> Doing lot of tries I've found out(I didn't know) that "make", when
> evaluates $(MAKEARGS) it works as expected and gives:
> Root MAKEARGS=-C /home/giuliobenetti/git/buildroot
> O=/home/giuliobenetti/git/build-br/.
> 
> BUT, when printing MAKEFLAGS with echo, it gives:
> Root MAKEFLAGS= --no-print-directory --
> 
> qt5base and every other package using $(MAKEFLAGS) under a *recipe* only will
> always evaluate $(MAKEFLAGS) as "--".
> Indeed if you try to use $(info $(MAKEFLAGS)) it will be different, without
> showing the 2 dashes.

 The difference between echo and $(info) is that echo is in a subshell and info
is not. So apparently, make doesn't just manipulate $(MAKEFLAGS) when it starts,
but also when it forks a subprocess.


> Going deeper I've found that those 2 dashes are appended only if you pass to
> MAKEARGS some variable like "O=/home/..."
> I mean, if you remove "O=/home/..." then MAKEFLAGS is "--no-print-directory" only.

 That is ...weird... because you do the echo in the outer make, which doesn't
know that MAKEARGS has any relation with MAKEFLAGS...


> The point is that MAKEARGS expects Makefile arguments only and not Variable as I
> understand. When you add variables, a "--" is appended between Make flags and
> Variables.

 Yes, when make starts, it reworks things so that the variables go into
MAKEOVERRIDES.


> One possible solution I thought is cleaning MAKEFLAGS from those isolated 2 dashes.

 I don't think that that's possible, because they're not really there.

> Before I thought to pass directly O=/home/.. when calling $(MAKE),
> but the problems comes out again, since in sub-makefile, that will be a MAKEARGS
> again.
> I don't see any different way to deny Make to emit "--".
> 
> This impacts MAKEFLAGS variable everywhere when evaluated under recipe like
> "echo $(MAKEFLAGS)" and it works in this way for both make-4.1 and make-3.82 too.
> 
> What do you think?

 What about swapping the -j and the MAKEFLAGS in qt5base? I.e.

	MAKEFLAGS="-j$(PARALLEL_JOBS) $(MAKEFLAGS)"

 Regards,
 Arnout
> 
> Happy easter and kind regards!

[Buildroot] Qt5 parallel build of qmake

[Giulio Benetti]

Hello Arnout,

Il 22/04/2019 09:56, Arnout Vandecappelle ha scritto:
> 
> 
> On 22/04/2019 00:43, Giulio Benetti wrote:
>> Hello Arnout, All,
>>
>> Il 21/04/2019 09:08, Arnout Vandecappelle ha scritto:
>>>
>>>
>>> On 18/04/2019 00:53, Giulio Benetti wrote:
>>>> Hi Arnout, All,
>>>>
>>>> Il 18/04/2019 00:16, Arnout Vandecappelle ha scritto:
>>>>>  ?? Hi all,
>>>>>
>>>>>  ?? I've put a few people in Cc that seem to be active users of Qt5.
>>>>>
>>>>>  ?? I noticed during a test build that during the configure step, qmake is built
>>>>> but not in parallel. I think it should be possible to enable parallel build for
>>>>> qmake by passing MAKE="$(MAKE)" in the environment during configuration. Would
>>>>> someone be interested in checking that out?
>>
>> I've found out which is the problem and where is its origin.
>>
>> On qt5base(and every other package using MAKEFLAGS) this:
>> MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
>> expands in this:
>> MAKEFLAGS=" --no-print-directory -- -j5"
>> so -j5 is ignored, then is not built in parallel.
>>
>> In:
>> https://git.buildroot.net/buildroot/tree/support/scripts/mkmakefile#n33
> 
>   Note that I observed the same issue without out-of-tree build, and anyway if I
> do out-of-tree build I always use explicit O= rather than the generated
> makefile. So the problem is not (only) due to mkmakefile.
> 
>>
>> basic Makefile is created with a dashed argument(-C to pass Buildroot Root
>> Makefile as argument), but then also O=... option is passed.
>>
>> Here is a snippet of my Makefile file created by mkmakefile script:
>> ...
>> MAKEARGS := -C /home/giuliobenetti/git/buildroot
>> MAKEARGS += O=$(if $(patsubst /%,,$(makedir)),$(CURDIR)/)$(patsubst
>> %/,%,$(makedir))
> 
>   Note that MAKEARGS is not a special variable for make...
> 
>>
>> MAKEFLAGS += --no-print-directory
> 
>   But MAKEFLAGS is. However, the MAKEFLAGS variable is always rebuilt by the new
> make process by combining the environment variable MAKEFLAGS with the command
> line options that are passed to it.
> 
> 
>> .PHONY: _all $(MAKECMDGOALS)
>>
>> all??? := $(filter-out Makefile,$(MAKECMDGOALS))
>>
>> _all:
>>  ????echo Root MAKEARGS=$(MAKEARGS)
>>  ????echo Root MAKEFLAGS=$(MAKEFLAGS)
>>  ????$(Q)umask 0022 && $(MAKE) $(MAKEARGS) $(all)
>> ...
>>
>> Doing lot of tries I've found out(I didn't know) that "make", when
>> evaluates $(MAKEARGS) it works as expected and gives:
>> Root MAKEARGS=-C /home/giuliobenetti/git/buildroot
>> O=/home/giuliobenetti/git/build-br/.
>>
>> BUT, when printing MAKEFLAGS with echo, it gives:
>> Root MAKEFLAGS= --no-print-directory --
>>
>> qt5base and every other package using $(MAKEFLAGS) under a *recipe* only will
>> always evaluate $(MAKEFLAGS) as "--".
>> Indeed if you try to use $(info $(MAKEFLAGS)) it will be different, without
>> showing the 2 dashes.
> 
>   The difference between echo and $(info) is that echo is in a subshell and info
> is not. So apparently, make doesn't just manipulate $(MAKEFLAGS) when it starts,
> but also when it forks a subprocess.

Yes, this is what I've noticed.

> 
>> Going deeper I've found that those 2 dashes are appended only if you pass to
>> MAKEARGS some variable like "O=/home/..."
>> I mean, if you remove "O=/home/..." then MAKEFLAGS is "--no-print-directory" only.
> 
>   That is ...weird... because you do the echo in the outer make, which doesn't
> know that MAKEARGS has any relation with MAKEFLAGS...

Right, the point is that MAKEARGS is passed to $(MAKE) as:
$(MAKE) $(MAKEARGS) $(all)

> 
>> The point is that MAKEARGS expects Makefile arguments only and not Variable as I
>> understand. When you add variables, a "--" is appended between Make flags and
>> Variables.
> 
>   Yes, when make starts, it reworks things so that the variables go into
> MAKEOVERRIDES.
> 
> 
>> One possible solution I thought is cleaning MAKEFLAGS from those isolated 2 dashes.
> 
>   I don't think that that's possible, because they're not really there.
> 
>> Before I thought to pass directly O=/home/.. when calling $(MAKE),
>> but the problems comes out again, since in sub-makefile, that will be a MAKEARGS
>> again.
>> I don't see any different way to deny Make to emit "--".
>>
>> This impacts MAKEFLAGS variable everywhere when evaluated under recipe like
>> "echo $(MAKEFLAGS)" and it works in this way for both make-4.1 and make-3.82 too.
>>
>> What do you think?
> 
>   What about swapping the -j and the MAKEFLAGS in qt5base? I.e.
> 
> 	MAKEFLAGS="-j$(PARALLEL_JOBS) $(MAKEFLAGS)"

That was my first idea, then trying to go deeper it took me out of the 
track.

Yes, this is the best solution.
In the beginning I thought it was Makefile introducing some "--" dirt, 
instead it is "make" that behaves that way when passing variables.
Also, MAKEFLAGS is not used very frequently.

So I go with swapping MAKEFLAGS and PARALLEL_JOBS.

Thank you
Best regards
-- 
Giulio Benetti
CTO

MICRONOVA SRL
Sede: Via A. Niedda 3 - 35010 Vigonza (PD)
Tel. 049/8931563 - Fax 049/8931346
Cod.Fiscale - P.IVA 02663420285
Capitale Sociale ? 26.000 i.v.
Iscritta al Reg. Imprese di Padova N. 02663420285
Numero R.E.A. 258642

>   Regards,
>   Arnout
>>
>> Happy easter and kind regards!

[Buildroot] [PATCH] package/qt5base: fix qmake parallel build

[Giulio Benetti]

When configuring qt5base, qmake is built, but it's not built in parallel
mode. This is due to MAKEFLAGS having 2 dashes on its tail, so this:
MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
expands in this(i.e. 5 njobs):
MAKEFLAGS="--no-print-directory -- -j5"
and -j5 gets ignored due to "--" preceeding -j5.
Double dashes are part of $(MAKEFLAGS) only when evaluated by shell.

Swap $(MAKEFLAGS) and -j$(PARALLEL_JOBS) to avoid having "--" before
-j$(PARALLEL_JOBS), this way -j$(PARALLEL_JOBS) won't be ignored by
./configure.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
---
 package/qt5/qt5base/qt5base.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/qt5/qt5base/qt5base.mk b/package/qt5/qt5base/qt5base.mk
index 0b45c50a66..e73b8931aa 100644
--- a/package/qt5/qt5base/qt5base.mk
+++ b/package/qt5/qt5base/qt5base.mk
@@ -324,7 +324,7 @@ define QT5BASE_CONFIGURE_CMDS
 	(cd $(@D); \
 		$(TARGET_MAKE_ENV) \
 		PKG_CONFIG="$(PKG_CONFIG_HOST_BINARY)" \
-		MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)" \
+		MAKEFLAGS="-j$(PARALLEL_JOBS) $(MAKEFLAGS)" \
 		./configure \
 		-v \
 		-prefix /usr \
-- 
2.17.1

[Buildroot] [PATCH] package/qt5base: fix qmake parallel build

[Michael Nazzareno Trimarchi]

Hi

On Mon, Apr 22, 2019 at 11:59 AM Giulio Benetti
<giulio.benetti@micronovasrl.com> wrote:
>
> When configuring qt5base, qmake is built, but it's not built in parallel
> mode. This is due to MAKEFLAGS having 2 dashes on its tail, so this:
> MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
> expands in this(i.e. 5 njobs):
> MAKEFLAGS="--no-print-directory -- -j5"
> and -j5 gets ignored due to "--" preceeding -j5.
> Double dashes are part of $(MAKEFLAGS) only when evaluated by shell.
>
> Swap $(MAKEFLAGS) and -j$(PARALLEL_JOBS) to avoid having "--" before
> -j$(PARALLEL_JOBS), this way -j$(PARALLEL_JOBS) won't be ignored by
> ./configure.
>
> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
> ---

Tested-by: Michael Trimarchi <michael@amarulasolutions.com>

Thank you

Michael
>  package/qt5/qt5base/qt5base.mk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/package/qt5/qt5base/qt5base.mk b/package/qt5/qt5base/qt5base.mk
> index 0b45c50a66..e73b8931aa 100644
> --- a/package/qt5/qt5base/qt5base.mk
> +++ b/package/qt5/qt5base/qt5base.mk
> @@ -324,7 +324,7 @@ define QT5BASE_CONFIGURE_CMDS
>         (cd $(@D); \
>                 $(TARGET_MAKE_ENV) \
>                 PKG_CONFIG="$(PKG_CONFIG_HOST_BINARY)" \
> -               MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)" \
> +               MAKEFLAGS="-j$(PARALLEL_JOBS) $(MAKEFLAGS)" \
>                 ./configure \
>                 -v \
>                 -prefix /usr \
> --
> 2.17.1
>
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot



-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |

[Buildroot] [PATCH] package/qt5base: fix qmake parallel build

[Thomas Petazzoni]

On Mon, 22 Apr 2019 11:58:42 +0200
Giulio Benetti <giulio.benetti@micronovasrl.com> wrote:

> When configuring qt5base, qmake is built, but it's not built in parallel
> mode. This is due to MAKEFLAGS having 2 dashes on its tail, so this:
> MAKEFLAGS="$(MAKEFLAGS) -j$(PARALLEL_JOBS)"
> expands in this(i.e. 5 njobs):
> MAKEFLAGS="--no-print-directory -- -j5"
> and -j5 gets ignored due to "--" preceeding -j5.
> Double dashes are part of $(MAKEFLAGS) only when evaluated by shell.
> 
> Swap $(MAKEFLAGS) and -j$(PARALLEL_JOBS) to avoid having "--" before
> -j$(PARALLEL_JOBS), this way -j$(PARALLEL_JOBS) won't be ignored by
> ./configure.
> 
> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
> ---
>  package/qt5/qt5base/qt5base.mk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied to master, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com