Re: [PATCH v2] systemd: Add hooks to stop/start xen-watchdog on suspend/resume

[Anthony PERARD <anthony@xxxxxxxxxxxxxx>]

On Thu, Jul 17, 2025 at 11:16:58PM +0300, Mykola Kvach wrote:
> diff --git a/m4/systemd.m4 b/m4/systemd.m4
> index ab12ea313d..ee684d3391 100644
> --- a/m4/systemd.m4
> +++ b/m4/systemd.m4
> @@ -28,6 +28,12 @@ AC_DEFUN([AX_SYSTEMD_OPTIONS], [
>               [set directory for systemd modules load files 
> [PREFIX/lib/modules-load.d/]]),
>               [SYSTEMD_MODULES_LOAD="$withval"], [SYSTEMD_MODULES_LOAD=""])
>       AC_SUBST(SYSTEMD_MODULES_LOAD)
> +
> +     AC_ARG_WITH(systemd-sleep,
> +             AS_HELP_STRING([--with-systemd-sleep=DIR],
> +             [set directory for systemd sleep script files 
> [PREFIX/lib/systemd/system-sleep/]]),
> +             [SYSTEMD_SLEEP_DIR="$withval"], [SYSTEMD_SLEEP_DIR=""])
> +     AC_SUBST(SYSTEMD_SLEEP_DIR)
>  ])
>  
>  AC_DEFUN([AX_ENABLE_SYSTEMD_OPTS], [
> @@ -69,6 +75,14 @@ AC_DEFUN([AX_CHECK_SYSTEMD_LIBS], [
>       AS_IF([test "x$SYSTEMD_MODULES_LOAD" = x], [
>           AC_MSG_ERROR([SYSTEMD_MODULES_LOAD is unset])
>       ], [])
> +
> +     AS_IF([test "x$SYSTEMD_SLEEP_DIR" = x], [
> +         SYSTEMD_SLEEP_DIR="\$(prefix)/lib/systemd/system-sleep/"

While reading this change, and systemd.m4, I notice a comment about
using pkg-config, well it's a comment about using it for $SYSTEMD_DIR,
but I believe it applies here too. It looks like we can replace this
hard-coded path by:

    PKG_CHECK_VAR([SYSTEMD_SLEEP_DIR], [systemd], [systemdsleepdir])

Which will query system-sleep path from the system. (This just run
`pkg-config --variable=systemdsleepdir systemd`, and store the result in
SYSTEMD_SLEEP_DIR) (The variable is now named "systemd_sleep_dir", but the
variable name without underscore is still available, and have been
available for longer.)

Is using PKG_CHECK_VAR would be fine with you?

> +     ], [])
> +
> +     AS_IF([test "x$SYSTEMD_SLEEP_DIR" = x], [
> +         AC_MSG_ERROR([SYSTEMD_SLEEP_DIR is unset])
> +     ], [])

After changing to use PKG_CHECK_VAR, I think this patch would be good to
go, so: Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
I can make the change on commit if that's ok.

And I need to remember to run `./autogen.sh` to regen the configure
scripts.

Thanks,

-- 
Anthony PERARD