[Buildroot] [PATCH 2/2] package/skeleton-init-sysv: conditionally enable swapon/swapoff in inittab
Carlos Santos
unixmania at gmail.com
Fri Feb 7 21:52:56 UTC 2020
On Thu, Feb 6, 2020 at 7:37 PM Peter Korsgaard <peter at korsgaard.com> wrote:
>
> >>>>> "unixmania" == unixmania <unixmania at gmail.com> writes:
>
> > From: Carlos Santos <unixmania at gmail.com>
> > The default inittab files added by busybox and sysvinit run 'swapon -a'
> > during init and 'swapoff -a' during shutdown but those programs are not
> > guaranteed to be available, so the boot log may become polluted by error
> > messages like this:
>
> > swapon: not found
>
> > To avoid this, make the swapon/swapoff lines in inittab optional.
>
> > - Add a BR2_SYSTEM_HAS_SWAPON_SWAPOFF config to inform that swapon and
> > swapoff are available.
>
> > - Add a BR2_PACKAGE_BUSYBOX_SWAPON_SWAPOFF config that depends on
> > BR2_USE_MMU and selects BR2_SYSTEM_HAS_SWAPON_SWAPOFF. Build the
> > Busybox swapon/swapoff utilities based on this new option.
>
> > - Make UTIL_LINUX_BINARIES select BR2_SYSTEM_HAS_SWAPON_SWAPOFF config.
>
> > - Add a targe-finalize hook to skeleton-init-sysv that comments-out or
> > enables the swapon/swapoff lines in /etc/inittab, based on the value
> > of BR2_SYSTEM_HAS_SWAPON_SWAPOFF.
>
> > Based on a previous patch sent by Thomas De Schampheleire.
>
> > Signed-off-by: Carlos Santos <unixmania at gmail.com>
> > ---
> > CC: Thomas De Schampheleire <thomas.de_schampheleire at nokia.com>
> > CC: Peter Korsgaard <peter at korsgaard.com>
> > ---
> > package/busybox/Config.in | 6 ++++++
> > package/busybox/busybox.mk | 14 ++++++++++++++
> > package/skeleton-init-sysv/skeleton-init-sysv.mk | 12 ++++++++++++
> > package/util-linux/Config.in | 1 +
> > system/Config.in | 6 ++++++
> > 5 files changed, 39 insertions(+)
>
> > diff --git a/package/busybox/Config.in b/package/busybox/Config.in
> > index 5e5c586762..9103256494 100644
> > --- a/package/busybox/Config.in
> > +++ b/package/busybox/Config.in
> > @@ -68,6 +68,12 @@ config BR2_PACKAGE_BUSYBOX_INDIVIDUAL_BINARIES
> > comment "Busybox individual binaries need a toolchain w/ dynamic library"
> > depends on BR2_STATIC_LIBS
>
> > +config BR2_PACKAGE_BUSYBOX_SWAPON_SWAPOFF
> > + bool
> > + default y
> > + depends on BR2_USE_MMU
> > + select BR2_SYSTEM_HAS_SWAPON_SWAPOFF # used by skeleton-init-sysv
>
> You are presumably missing some option text here so this becomes a
> visible option in menuconfig.
>
>
>
> > +ifeq ($(BR2_PACKAGE_BUSYBOX_SWAPON_SWAPOFF),y)
> > +define BUSYBOX_SET_SWAPON_SWAPOFF
> > + $(call KCONFIG_ENABLE_OPT,CONFIG_SWAPON,$(BUSYBOX_BUILD_CONFIG))
> > + $(call KCONFIG_ENABLE_OPT,CONFIG_SWAPOFF,$(BUSYBOX_BUILD_CONFIG))
> > + $(call KCONFIG_ENABLE_OPT,CONFIG_FEATURE_SWAPONOFF_LABEL,$(BUSYBOX_BUILD_CONFIG))
> > +endef
> > +else
> > +define BUSYBOX_SET_SWAPON_SWAPOFF
> > + $(call KCONFIG_DISABLE_OPT,CONFIG_SWAPON,$(BUSYBOX_BUILD_CONFIG))
> > + $(call KCONFIG_DISABLE_OPT,CONFIG_SWAPOFF,$(BUSYBOX_BUILD_CONFIG))
> > +endef
> > +endif
>
> I am not really convinced that this is an improvement over Thomas'
> version. In general I think we should keep the .config tweaks to a
> minimum as it can be quite confusing to users that their (potentially
> custom) .config settings is overridden.
>
> Do you see any functional issue with the swapon/off handling as is, or
> is it just a question of "taste"?
>
> --
> Bye, Peter Korsgaard
I must admit that it's mostly a matter of taste. Thinking better I
believe that a much simpler approach is possible.
--
Carlos Santos <unixmania at gmail.com>
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