s390: enable ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT

Deferred struct page initialization works on s390. However it makes
only sense for the fake numa case, since the kthreads that initialize
struct pages are started per node. Without fake numa there is just a
single node and therefore no gain.
However there is no reason to not enable this feature. Therefore
select the config option and enable the feature in all config files.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -105,6 +105,7 @@ config S390
 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF

arch/s390/configs/default_defconfig

@@ -73,6 +73,7 @@ CONFIG_ZSWAP=y
 CONFIG_ZBUD=m
 CONFIG_ZSMALLOC=m
 CONFIG_ZSMALLOC_STAT=y
+CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
 CONFIG_IDLE_PAGE_TRACKING=y
 CONFIG_PCI=y
 CONFIG_PCI_DEBUG=y

arch/s390/configs/gcov_defconfig

@@ -72,6 +72,7 @@ CONFIG_ZSWAP=y
 CONFIG_ZBUD=m
 CONFIG_ZSMALLOC=m
 CONFIG_ZSMALLOC_STAT=y
+CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
 CONFIG_IDLE_PAGE_TRACKING=y
 CONFIG_PCI=y
 CONFIG_HOTPLUG_PCI=y

arch/s390/configs/performance_defconfig

@@ -70,6 +70,7 @@ CONFIG_ZSWAP=y
 CONFIG_ZBUD=m
 CONFIG_ZSMALLOC=m
 CONFIG_ZSMALLOC_STAT=y
+CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
 CONFIG_IDLE_PAGE_TRACKING=y
 CONFIG_PCI=y
 CONFIG_HOTPLUG_PCI=y