[Buildroot] [PATCH v2] qt5webengine: propagate parallel flag to ninja

[Buildroot] [PATCH v2] qt5webengine: propagate parallel flag to ninja

[Gaël PORTAY]

WebEngine is a big project to build. It uses ninja which is a build
system that does everything in parallel[1].

	Builds are always run in parallel, based by default on the number of
	CPUs your system has. Underspecified build dependencies will result in
	incorrect builds.

QtWebEngine does not propagate the parallel flag from the running
instance of make to ninja. Thus, all the machine cores are used to build
this single project.

	make -j 10 -> ninja -j # all cores

This behavior disrupts powerful machines which are setup to build many
projects in parallel. Even worse, the build fails on machines where the
ratio CPU-cores / amount of RAM (including swap) is not appropriate. g++
may have not enough of memory to build all those files in parallel.

Unfortunatly, the target `run_ninja' is hardcoded in the Makefile
src/core/Makefile.run_gn; there is no way to propagate flags using a
variable through the make command-line.

	run_ninja:
	        /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/3rdparty/ninja/ninja
-C /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/core/release QtWebEngineCore

Luckily, the Qt gn_run.pro[2] can hardcode ninja extra flags through the
variable NINJAFLAGS when the Makefile is generated (which is performed
during the build and not during configure step).

This commit sets the NINJAFLAGS using the variable PARALLEL_JOBS to limit
the number of cores used by ninja.

Fixes:
	virtual memory exhausted: Cannot allocate memory

[1]: https://ninja-build.org/manual.html#_comparison_to_make
[2]: https://github.com/qt/qtwebengine/blob/v5.11.1/src/core/gn_run.pro#L49-L53

CC: Damien Riegel <damien.riegel@savoirfairelinux.com>
CC: Jean-Fran?ois T?tu <jean-francois.tetu@savoirfairelinux.com>
Signed-off-by: Ga?l PORTAY <gael.portay@savoirfairelinux.com>
---
Changes since v1:
 - Use PARALLEL_JOBS instead of BR2_JLEVEL
 - Reword commit message

 package/qt5/qt5webengine/qt5webengine.mk | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/package/qt5/qt5webengine/qt5webengine.mk b/package/qt5/qt5webengine/qt5webengine.mk
index 08120421d6..2c622c91ba 100644
--- a/package/qt5/qt5webengine/qt5webengine.mk
+++ b/package/qt5/qt5webengine/qt5webengine.mk
@@ -48,6 +48,8 @@ define QT5WEBENGINE_PYTHON2_SYMLINK
 endef
 QT5WEBENGINE_PRE_CONFIGURE_HOOKS += QT5WEBENGINE_PYTHON2_SYMLINK
 
+QT5WEBENGINE_ENV += NINJAFLAGS="-j$(PARALLEL_JOBS)"
+
 ifeq ($(BR2_PACKAGE_QT5_VERSION_LATEST),y)
 define QT5WEBENGINE_CREATE_HOST_PKG_CONFIG
 	sed s%@HOST_DIR@%$(HOST_DIR)%g $(QT5WEBENGINE_PKGDIR)/host-pkg-config.in > $(@D)/host-bin/host-pkg-config
-- 
2.17.1

[Buildroot] [PATCH v2] qt5webengine: propagate parallel flag to ninja

[Yann E. MORIN]

Ga?l, All,

On 2018-06-29 10:35 -0400, Ga?l PORTAY spake thusly:
> WebEngine is a big project to build. It uses ninja which is a build
> system that does everything in parallel[1].
> 
> 	Builds are always run in parallel, based by default on the number of
> 	CPUs your system has. Underspecified build dependencies will result in
> 	incorrect builds.
> 
> QtWebEngine does not propagate the parallel flag from the running
> instance of make to ninja. Thus, all the machine cores are used to build
> this single project.
> 
> 	make -j 10 -> ninja -j # all cores
> 
> This behavior disrupts powerful machines which are setup to build many
> projects in parallel. Even worse, the build fails on machines where the
> ratio CPU-cores / amount of RAM (including swap) is not appropriate. g++
> may have not enough of memory to build all those files in parallel.
> 
> Unfortunatly, the target `run_ninja' is hardcoded in the Makefile
> src/core/Makefile.run_gn; there is no way to propagate flags using a
> variable through the make command-line.
> 
> 	run_ninja:
> 	        /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/3rdparty/ninja/ninja
> -C /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/core/release QtWebEngineCore
> 
> Luckily, the Qt gn_run.pro[2] can hardcode ninja extra flags through the
> variable NINJAFLAGS when the Makefile is generated (which is performed
> during the build and not during configure step).
> 
> This commit sets the NINJAFLAGS using the variable PARALLEL_JOBS to limit
> the number of cores used by ninja.
> 
> Fixes:
> 	virtual memory exhausted: Cannot allocate memory
> 
> [1]: https://ninja-build.org/manual.html#_comparison_to_make
> [2]: https://github.com/qt/qtwebengine/blob/v5.11.1/src/core/gn_run.pro#L49-L53
> 
> CC: Damien Riegel <damien.riegel@savoirfairelinux.com>
> CC: Jean-Fran?ois T?tu <jean-francois.tetu@savoirfairelinux.com>
> Signed-off-by: Ga?l PORTAY <gael.portay@savoirfairelinux.com>

Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

Regards,
Yann E. MORIN.

> ---
> Changes since v1:
>  - Use PARALLEL_JOBS instead of BR2_JLEVEL
>  - Reword commit message
> 
>  package/qt5/qt5webengine/qt5webengine.mk | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/package/qt5/qt5webengine/qt5webengine.mk b/package/qt5/qt5webengine/qt5webengine.mk
> index 08120421d6..2c622c91ba 100644
> --- a/package/qt5/qt5webengine/qt5webengine.mk
> +++ b/package/qt5/qt5webengine/qt5webengine.mk
> @@ -48,6 +48,8 @@ define QT5WEBENGINE_PYTHON2_SYMLINK
>  endef
>  QT5WEBENGINE_PRE_CONFIGURE_HOOKS += QT5WEBENGINE_PYTHON2_SYMLINK
>  
> +QT5WEBENGINE_ENV += NINJAFLAGS="-j$(PARALLEL_JOBS)"
> +
>  ifeq ($(BR2_PACKAGE_QT5_VERSION_LATEST),y)
>  define QT5WEBENGINE_CREATE_HOST_PKG_CONFIG
>  	sed s%@HOST_DIR@%$(HOST_DIR)%g $(QT5WEBENGINE_PKGDIR)/host-pkg-config.in > $(@D)/host-bin/host-pkg-config
> -- 
> 2.17.1
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'

[Buildroot] [PATCH v2] qt5webengine: propagate parallel flag to ninja

[Thomas Petazzoni]

Hello,

On Fri, 29 Jun 2018 10:35:21 -0400, Ga?l PORTAY wrote:
> WebEngine is a big project to build. It uses ninja which is a build
> system that does everything in parallel[1].
> 
> 	Builds are always run in parallel, based by default on the number of
> 	CPUs your system has. Underspecified build dependencies will result in
> 	incorrect builds.
> 
> QtWebEngine does not propagate the parallel flag from the running
> instance of make to ninja. Thus, all the machine cores are used to build
> this single project.
> 
> 	make -j 10 -> ninja -j # all cores
> 
> This behavior disrupts powerful machines which are setup to build many
> projects in parallel. Even worse, the build fails on machines where the
> ratio CPU-cores / amount of RAM (including swap) is not appropriate. g++
> may have not enough of memory to build all those files in parallel.
> 
> Unfortunatly, the target `run_ninja' is hardcoded in the Makefile
> src/core/Makefile.run_gn; there is no way to propagate flags using a
> variable through the make command-line.
> 
> 	run_ninja:
> 	        /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/3rdparty/ninja/ninja
> -C /home/gportay/src/buildroot/output-qt5.11/build/qt5webengine-5.11.1/src/core/release QtWebEngineCore
> 
> Luckily, the Qt gn_run.pro[2] can hardcode ninja extra flags through the
> variable NINJAFLAGS when the Makefile is generated (which is performed
> during the build and not during configure step).
> 
> This commit sets the NINJAFLAGS using the variable PARALLEL_JOBS to limit
> the number of cores used by ninja.
> 
> Fixes:
> 	virtual memory exhausted: Cannot allocate memory
> 
> [1]: https://ninja-build.org/manual.html#_comparison_to_make
> [2]: https://github.com/qt/qtwebengine/blob/v5.11.1/src/core/gn_run.pro#L49-L53
> 
> CC: Damien Riegel <damien.riegel@savoirfairelinux.com>
> CC: Jean-Fran?ois T?tu <jean-francois.tetu@savoirfairelinux.com>
> Signed-off-by: Ga?l PORTAY <gael.portay@savoirfairelinux.com>
> ---
> Changes since v1:
>  - Use PARALLEL_JOBS instead of BR2_JLEVEL
>  - Reword commit message

Applied to master, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com