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Date:   Sat, 29 Jul 2023 08:44:32 +0200
From:   Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <thomas@t-8ch.de>
To:     Zhangjin Wu <falcon@tinylab.org>
Cc:     w@1wt.eu, arnd@arndb.de, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v3 12/12] selftests/nolibc: speed up some targets with
 multiple jobs
Message-ID: <ce2f10ad-bbdf-4948-b784-b497e8973e6e@t-8ch.de>
References: <cover.1690489039.git.falcon@tinylab.org>
 <ca03989b38085a74bde33b7dc5040b33a76f3c4b.1690489039.git.falcon@tinylab.org>
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On 2023-07-28 04:35:01+0800, Zhangjin Wu wrote:
> The sysroot install and kernel build targets are time cost, let's use
> -j<N> to parallelize them with multiple jobs.
> 
> Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
> ---
>  tools/testing/selftests/nolibc/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
> index ad2538ec5eb0..1b45c22f9a94 100644
> --- a/tools/testing/selftests/nolibc/Makefile
> +++ b/tools/testing/selftests/nolibc/Makefile
> @@ -171,7 +171,7 @@ PHONY = sysroot/$(ARCH)/include
>  sysroot/$(ARCH)/include:
>  	$(Q)rm -rf sysroot/$(ARCH) sysroot/sysroot
>  	$(QUIET_MKDIR)mkdir -p sysroot
> -	$(Q)$(MAKE) -C ../../../include/nolibc ARCH=$(ARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone
> +	$(Q)$(MAKE) -j$$(nproc) -C ../../../include/nolibc ARCH=$(ARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone

This should already work when the users specify -j on the make command
line themselves.
I'm not a fan of force-enabling it here.

>  	$(Q)mv sysroot/sysroot sysroot/$(ARCH)
>  
>  ifneq ($(NOLIBC_SYSROOT),0)
> @@ -211,7 +211,7 @@ initramfs: nolibc-test
>  	$(Q)cp nolibc-test initramfs/init
>  
>  # common macros for kernel targets
> -MAKE_KERNEL   = $(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE)
> +MAKE_KERNEL   = $(MAKE) -j$$(nproc) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE)
>  KERNEL_CONFIG = $(objtree)/.config
>  KERNEL_IMAGE  = $(objtree)/$(IMAGE)
>  
> -- 
> 2.25.1
>