Bug#946456: systemd: Provide systemd-sysusers as an independent package

[Zbigniew Jędrzejewski-Szmek]

On Thu, Jan 30, 2020 at 11:51:48PM -0300, Felipe Sateler wrote:
> On Thu, Jan 30, 2020 at 6:40 PM Michael Biebl <biebl at debian.org> wrote:
> 
> > Hi Felipe
> >
> > Am 30.01.20 um 22:30 schrieb Felipe Sateler:
> > >
> > >
> > > On Thu, Jan 30, 2020 at 1:39 PM Michael Biebl <biebl at debian.org
> > > <mailto:biebl at debian.org>> wrote:
> > >
> > >     Am 28.01.20 um 17:27 schrieb Ansgar:
> > >     > On Tue, 2020-01-28 at 16:51 +0100, Michael Biebl wrote:
> > >     >> Am 28.01.20 um 14:59 schrieb Ansgar:
> > >     >>> I tried linking systemd-{sysusers,tmpfiles} statically against
> > >     >>> systemd's private library earlier this month.  It increases the
> > >     >>> binaries size by ~100 kB (compared to Installed-Size: 14.2 MB of
> > >     >>> systemd that is just one percent).
> > >     >>
> > >     >> Is that 100K per binary?
> > >     >
> > >     > I checked my notes at it was 100 kB per binary: they are 212 kB
> > larger
> > >     > (sysusers 51 kB → 137 kB, tmpfiles 84 kB → 212 kB); I tested with
> > >     > systemd 243-8.
> > >     >
> > >     > It might be possible to make it a bit smaller if one was to somehow
> > >     > link libsystemd0 for functions available there (libsystemd-shared
> > >     > currently duplicates those).
> > >
> > >
> > > That is not possible. There is global state that is not to be shared.
> > > See https://github.com/systemd/systemd/pull/3516#issuecomment-227482524
> >
> > What's your thought on how to solve this libsystemd-shared issue should
> > we consider splitting out systemd-{sysusers,tmpfiles}
> >
> > - link statically (and carry a downstream patch for eternity)
> > - move libsystemd-shared to systemd-utils and risk the breakage that can
> > result from a partial/aborted upgrade
> > - copy, instead of move, the binaries + libsystemd-shared and make the
> > resulting systemd-utils package Conflict with systemd (instead of having
> > systemd depend on systemd-utils)
> > - something else?
> >
> 
> I tried linking statically the "can run without systemd-pid1 tools" with
> the attached patch.
> 
> Disk usage appears to increase by about 400 kb:
> % dpkg --info systemd_244.1-1_amd64.deb|grep Installed
> 
>  Installed-Size: 13908
> % dpkg --info ../systemd_244-3_amd64.deb|grep Installed
>  Installed-Size: 14319
> 
> Maybe upstream can be persuaded to merge something like this?
> 
> -- 
> 
> Saludos,
> Felipe Sateler

> diff --git a/meson.build b/meson.build
> index b8dff8cd94..39cef6b301 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1493,6 +1493,29 @@ make_autosuspend_rules_py = find_program('tools/make-autosuspend-rules.py')
>  
>  ############################################################
>  
> +
> +libutil = static_library(
> +        'util',
> +        [
> +                'src/shared/acl-util.c',
> +                'src/shared/enable-mempool.c',
> +                'src/shared/id128-print.c',
> +                'src/shared/pager.c',
> +                'src/shared/path-lookup.c',
> +                'src/shared/pretty-print.c',
> +                'src/shared/spawn-ask-password-agent.c',
> +                'src/shared/spawn-polkit-agent.c',
> +                'src/shared/specifier.c',
> +                'src/shared/sysctl-util.c',
> +                'src/shared/sysctl-util.h',
> +                'src/shared/tmpfile-util-label.c',
> +                'src/shared/uid-range.c',
> +                'src/shared/verbs.c',
> +        ] + id128_sources,
> +        link_with: [libbasic, libsystemd_static],
> +        include_directories: includes
> +)

Is creating a separate static library actually necessary?  What would
the results be if those binaries were linked to the static version of
libshared that we already provide support for? I hope the compiler
would be able to drop any unused objects and achieve the same size,
without having to maintain yet another list of files.

>  # binaries that have --help and are intended for use by humans,
>  # usually, but not always, installed in /bin.
>  public_programs = []
> @@ -1537,6 +1560,7 @@ test_dlopen = executable(
>          include_directories : includes,
>          link_with : [libbasic],
>          dependencies : [libdl],
> +        b_lto: false,
>          build_by_default : want_tests != 'false')
>  
>  foreach tuple : [['myhostname', 'ENABLE_NSS_MYHOSTNAME'],
> @@ -2407,7 +2431,7 @@ install_data('src/sleep/sleep.conf',
>  exe = executable('systemd-sysctl',
>                   'src/sysctl/sysctl.c',
>                   include_directories : includes,
> -                 link_with : [libshared],
> +                 link_with : [libutil],

To upstream this, the change in behaviour must be configuration-time
selectable.

Zbyszek