[Buildroot] [PATCH 1/2] Revert "package/pkg-utils.mk: break hardlinks in global {TARGET, HOST}_DIR on per-package build"

[Herve Codina]

Hi Yann,

On Tue, 17 Oct 2023 23:01:19 +0200
"Yann E. MORIN" <yann.morin.1998 at free.fr> wrote:

> Commit 21d52e52d8de (package/pkg-utils.mk: break hardlinks in global
> {TARGET, HOST}_DIR on per-package build) stopped hardlink the source and
> destination when rsyncing per-package directory, on the rationale that
> modifying files in-place after the rsync would also modify the original
> file, and that break foo-rebuild and can cause issues with post-build
> scripts.
> 
> However, what 21d52e52d8de did not envision, is that copying instead of
> hard-linking has two nasty side effects:
> 
>   - the size increase for the build directory increase with the number
>     of packages and with the depth of th dependency chains for those
>     packages: a (relatively small) build that was previously totalling
>     ~13GiB in output/, now totals north of 122GiB, an almost 10-time
>     increase;
> 
>   - the build time increases, as it takes mopre time to read+write files

s/mopre/more

>     than it takes to create a new link to a file; the same build saw a

an increase

>     increase of build time from 5min 10s to 7min 30s, a 45% increase.
> 
> These regressions are both serious, so revert the change; we'll come up
> with a stopgap measure in follow-up commits.
> 
> This reverts commit 21d52e52d8dee0940d28b3a38551eb183be37813.
> 
> Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
> Cc: Herve Codina <herve.codina at bootlin.com>
> Cc: Peter Korsgaard <peter at korsgaard.com>
> Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>

With the typo fixed:
Reviewed-by: Herve Codina <herve.codina at bootlin.com>

Best regards,
Hervé