mm: avoid setting up anonymous pages into file mapping

[uclinux-h8/linux.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index c180af8..e79de2b 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -636,3 +636,21 @@ config MAX_STACK_SIZE_MB
          changed to a smaller value in which case that is used.
 
          A sane initial value is 80 MB.
+
+# For architectures that support deferred memory initialisation
+config ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
+       bool
+
+config DEFERRED_STRUCT_PAGE_INIT
+       bool "Defer initialisation of struct pages to kswapd"
+       default n
+       depends on ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
+       depends on MEMORY_HOTPLUG
+       help
+         Ordinarily all struct pages are initialised during early boot in a
+         single thread. On very large machines this can take a considerable
+         amount of time. If this option is set, large machines will bring up
+         a subset of memmap at boot and then initialise the rest in parallel
+         when kswapd starts. This has a potential performance impact on
+         processes running early in the lifetime of the systemm until kswapd
+         finishes the initialisation.