[Buildroot] [PATCH 2/2] package/skeleton-init-sysv: conditionally enable swapon/swapoff in inittab

Peter Korsgaard peter at korsgaard.com
Thu Feb 6 22:37:20 UTC 2020


>>>>> "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



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