Re: [PATCH v3] linux-custom: Speedup build of target specific linux-kbuild package

[Uladzimir Bely <ubely@ilbers.de>]

On Mon, 2024-06-10 at 17:44 +0200, Stefan Koch wrote:
> Avoids time expensive QEMU-emulated merging of kernel config by using
> the existing kernel config for the target specific linux-kbuild.
> The host specific linux-kbuild package
> uses the existing kernel config, too.
> 
> Using DEPENDS instead of RDEPENDS ensures creation of
> kernel (including config) before build of
> target and host specific linux-kbuild packages.
> 
> Signed-off-by: Stefan Koch <stefan-koch@siemens.com>
> ---
>  .../linux/files/debian/isar/configure.tmpl    | 22 +++++++++++++++--
> --
>  meta/recipes-kernel/linux/linux-custom.inc    | 11 +++++++---
>  2 files changed, 26 insertions(+), 7 deletions(-)
> 
> diff --git a/meta/recipes-
> kernel/linux/files/debian/isar/configure.tmpl b/meta/recipes-
> kernel/linux/files/debian/isar/configure.tmpl
> index 389c9a85..73f554ed 100644
> --- a/meta/recipes-kernel/linux/files/debian/isar/configure.tmpl
> +++ b/meta/recipes-kernel/linux/files/debian/isar/configure.tmpl
> @@ -10,10 +10,24 @@ do_configure() {
>      # Trace what we do here
>      set -x
>  
> -    # Process kernel config target and fragments
> -    ${MAKE} O=${KERNEL_BUILD_DIR} ${KERNEL_CONFIG_TARGET}
> -    ./scripts/kconfig/merge_config.sh -O ${KERNEL_BUILD_DIR}/ \
> -        ${KERNEL_BUILD_DIR}/.config ${KERNEL_CONFIG_FRAGMENTS}
> +    kernelconfig="$(find /boot -maxdepth 1 -name "config-${PV}*" -
> print -quit)"
> +    if echo "${DEB_BUILD_PROFILES}" | grep -q "kbuild" && \
> +       ! echo "${DEB_BUILD_PROFILES}" | grep -q "kernel" && \
> +       [ -e "${kernelconfig}" ]; then
> +        # Prefer existing kernel config
> +        # So, very expensive QEMU-emulated merge_config.sh
> +        # can be skipped for target specific linux-kbuild package
> +        # The host specific linux-kbuild package
> +        # uses the existing kernel config, too.
> +        mkdir -p ${KERNEL_BUILD_DIR}
> +        cp "${kernelconfig}" ${KERNEL_BUILD_DIR}/.config
> +        ${MAKE} O=${KERNEL_BUILD_DIR} olddefconfig
> +    else
> +        # Process kernel config target and fragments
> +        ${MAKE} O=${KERNEL_BUILD_DIR} ${KERNEL_CONFIG_TARGET}
> +        ./scripts/kconfig/merge_config.sh -O ${KERNEL_BUILD_DIR}/ \
> +            ${KERNEL_BUILD_DIR}/.config ${KERNEL_CONFIG_FRAGMENTS}
> +    fi
>  
>      # Stop tracing
>      set +x
> diff --git a/meta/recipes-kernel/linux/linux-custom.inc
> b/meta/recipes-kernel/linux/linux-custom.inc
> index 647f09dd..6aa70fd3 100644
> --- a/meta/recipes-kernel/linux/linux-custom.inc
> +++ b/meta/recipes-kernel/linux/linux-custom.inc
> @@ -25,6 +25,7 @@ KBUILD_DEPENDS ?= "build-essential:native, \
>                     flex, \
>                     git, \
>                     kmod, \
> +                   linux-image-
> ${KERNEL_NAME_PROVIDED}:${DISTRO_ARCH} <kbuild !kernel>, \
>                     rsync,"
>  
>  KERNEL_DEBIAN_DEPENDS ?= "initramfs-tools | linux-initramfs-tool, \
> @@ -112,7 +113,7 @@ BUILD_PROFILES = "kernel kbuild"
>  BBCLASSEXTEND:append:cross-profile = " kbuildtarget"
>  
>  # When cross-profile is active:
> -# build only kernel with the default variant of the recipe
> +# build only kernel (including config) with the default variant of
> the recipe
>  BUILD_PROFILES:cross-profile = "kernel"
>  
>  # -native: kbuild package for host
> @@ -122,14 +123,18 @@ RECIPE_PROVIDES:class-native = " \
>      linux-kbuild-${KERNEL_NAME_PROVIDED}"
>  # Use pseudo target to pull in the base variant of the recipe.
>  # Will be auto-extended with -native by multiarch.bbclass.
> -RDEPENDS:class-native += "${BPN}-pseudo"
> +# Using DEPENDS instead of RDEPENDS to ensure creation of kernel
> including
> +# pregenerated kernel config before host specific linux-kbuild
> package build
> +DEPENDS:class-native += "${BPN}-pseudo"
>  
>  # -kbuildtarget: kbuild package for target, enforcing non-cross-
> build
>  BUILD_PROFILES:class-kbuildtarget = "kbuild"
>  RECIPE_PROVIDES:class-kbuildtarget = " \
>      linux-headers-${KERNEL_NAME_PROVIDED} \
>      linux-kbuild-${KERNEL_NAME_PROVIDED}"
> -RDEPENDS:class-kbuildtarget = "${BPN}"
> +# Using DEPENDS instead of RDEPENDS to ensure creation of kernel
> including
> +# pregenerated kernel config before target specific linux-kbuild
> package build
> +DEPENDS:class-kbuildtarget = "${BPN}"
>  ISAR_CROSS_COMPILE:class-kbuildtarget = "0"
>  
>  # Make bitbake know we will be producing linux-image and linux-
> headers packages

Applied to next, thanks.

-- 
Best regards,
Uladzimir.