Hi Jose,
On Thu, Aug 01, 2024 at 07:29:40AM -0600, Jose Fernandez wrote:
> Add a new -debug package to the pacman PKGBUILD that will contain the
> vmlinux image for debugging purposes. This package depends on the
> -headers package and will be installed in /usr/src/debug/${pkgbase}.
>
> The vmlinux image is needed to debug core dumps with tools like crash.
>
> Signed-off-by: Jose Fernandez <jose.fernandez@xxxxxxxxx>
> Reviewed-by: Peter Jung <ptr1337@xxxxxxxxxxx>
This appears to add a non-trivial amount of time to the build when benchmarking
with Arch Linux's configuration (I measure 9% with hyperfine):
Benchmark 1: pacman-pkg @ 21b136cc63d2 ("minmax: fix up min3() and max3() too")
Time (mean ± σ): 579.541 s ± 0.585 s [User: 22156.731 s, System: 3681.698 s]
Range (min … max): 578.894 s … 580.033 s 3 runs
Benchmark 2: pacman-pkg @ c5af4db0563b ("kbuild: add debug package to pacman PKGBUILD")
Time (mean ± σ): 633.419 s ± 0.972 s [User: 22247.886 s, System: 3673.879 s]
Range (min … max): 632.302 s … 634.070 s 3 runs
Summary
pacman-pkg @ 21b136cc63d2 ("minmax: fix up min3() and max3() too") ran
1.09 ± 0.00 times faster than pacman-pkg @ c5af4db0563b ("kbuild: add debug package to pacman PKGBUILD")
It would be nice to add some option to avoid building this package for
developers who may not want it (I know I personally would not want it
with that penalty because I do a lot of bisects) or maybe adding a
target to build this package with the rest like 'pacman-pkg-with-dbg' or
something? Also, couldn't vmlinux be obtained from vmlinuz that already
exists in the main package via scripts/extract-vmlinux?
Cheers,
Nathan
> ---
> scripts/package/PKGBUILD | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/scripts/package/PKGBUILD b/scripts/package/PKGBUILD
> index 663ce300dd06..beda3db21863 100644
> --- a/scripts/package/PKGBUILD
> +++ b/scripts/package/PKGBUILD
> @@ -6,6 +6,7 @@ pkgbase=${PACMAN_PKGBASE:-linux-upstream}
> pkgname=("${pkgbase}" "${pkgbase}-api-headers")
> if grep -q CONFIG_MODULES=y include/config/auto.conf; then
> pkgname+=("${pkgbase}-headers")
> + pkgname+=("${pkgbase}-debug")
> fi
> pkgver="${KERNELRELEASE//-/_}"
> # The PKGBUILD is evaluated multiple times.
> @@ -89,6 +90,15 @@ _package-headers() {
> ln -sr "${builddir}" "${pkgdir}/usr/src/${pkgbase}"
> }
>
> +_package-debug(){
> + pkgdesc="Non-stripped vmlinux file for the ${pkgdesc} kernel"
> + depends=(${pkgbase}-headers)
> +
> + cd "${objtree}"
> + mkdir -p "$pkgdir/usr/src/debug/${pkgbase}"
> + install -Dt "$pkgdir/usr/src/debug/${pkgbase}" -m644 vmlinux
> +}
> +
> _package-api-headers() {
> pkgdesc="Kernel headers sanitized for use in userspace"
> provides=(linux-api-headers)
> --
> 2.46.0
>
