Re: [PATCH v2] builddeb: parallelize debug module installation

[Riku Voipio]

On 27 April 2015 at 19:43, Chris J Arges <chris.j.arges@xxxxxxxxxxxxx> wrote:
> When building the dbg package, we use a large 'for module in $(find' loop that
> can be easily parallelized by using 'find | xargs'. This patch modifies this
> loop to use the later paradigm.
>
> In addition, ensure we add '-n1 -P0' to xargs to run as many processes as
> possible.
>
> Signed-off-by: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
> ---
>  scripts/package/builddeb | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/scripts/package/builddeb b/scripts/package/builddeb
> index 88dbf23..538f829 100755
> --- a/scripts/package/builddeb
> +++ b/scripts/package/builddeb
> @@ -152,16 +152,17 @@ if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then
>                 rmdir "$tmpdir/lib/modules/$version"
>         fi
>         if [ -n "$BUILD_DEBUG" ] ; then
> -               for module in $(find $tmpdir/lib/modules/ -name *.ko -printf '%P\n'); do
> -                       module=lib/modules/$module
> -                       mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module)
> +               find $tmpdir/lib/modules/ -name *.ko -printf '%P\n' | xargs -n1 -P0 -I {} sh -c '

I would go with -P`getconf _NPROCESSORS_ONLN`. There can be thousands
of modules (allmodconfig will make 4500).

> +                       mkdir -p $(dirname '"$dbg_dir"'/usr/lib/debug/lib/modules/$1);'"
>                         # only keep debug symbols in the debug file
> -                       $OBJCOPY --only-keep-debug $tmpdir/$module $dbg_dir/usr/lib/debug/$module
> +                       $OBJCOPY --only-keep-debug $tmpdir/lib/modules/{} \
> +                               $dbg_dir/usr/lib/debug/lib/modules/{};
>                         # strip original module from debug symbols
> -                       $OBJCOPY --strip-debug $tmpdir/$module
> +                       $OBJCOPY --strip-debug $tmpdir/lib/modules/{};
>                         # then add a link to those
> -                       $OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $tmpdir/$module
> -               done
> +                       $OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/lib/modules/{} \
> +                               $tmpdir/lib/modules/{};
> +               " -- {}
>         fi
>  fi
>
> --
> 1.9.1
>
> --
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