If unsure, choose this option (Flat Memory) over any other.
config DISCONTIGMEM_MANUAL
- bool "Discontigious Memory"
+ bool "Discontiguous Memory"
depends on ARCH_DISCONTIGMEM_ENABLE
help
This option provides enhanced support for discontiguous
memory hotplug systems. This is normal.
For many other systems, this will be an alternative to
- "Discontigious Memory". This option provides some potential
+ "Discontiguous Memory". This option provides some potential
performance benefits, along with decreased code complexity,
but it is newer, and more experimental.
def_bool y
depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
+#
+# SPARSEMEM_EXTREME (which is the default) does some bootmem
+# allocations when memory_present() is called. If this can not
+# be done on your architecture, select this option. However,
+# statically allocating the mem_section[] array can potentially
+# consume vast quantities of .bss, so be careful.
+#
+# This option will also potentially produce smaller runtime code
+# with gcc 3.4 and later.
+#
+config SPARSEMEM_STATIC
+ def_bool n
+
#
# Architectecture platforms which require a two level mem_section in SPARSEMEM
# must select this option. This is usually for architecture platforms with
# an extremely sparse physical address space.
#
-config ARCH_SPARSEMEM_EXTREME
- def_bool n
- depends on SPARSEMEM && 64BIT
+config SPARSEMEM_EXTREME
+ def_bool y
+ depends on SPARSEMEM && !SPARSEMEM_STATIC
+
+# eventually, we can have this option just 'select SPARSEMEM'
+config MEMORY_HOTPLUG
+ bool "Allow for memory hot-add"
+ depends on SPARSEMEM && HOTPLUG && !SOFTWARE_SUSPEND
+
+comment "Memory hotplug is currently incompatible with Software Suspend"
+ depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND
+
+# Heavily threaded applications may benefit from splitting the mm-wide
+# page_table_lock, so that faults on different parts of the user address
+# space can be handled with less contention: split it at this NR_CPUS.
+# Default to 4 for wider testing, though 8 might be more appropriate.
+# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
+# PA-RISC's debug spinlock_t is too large for the 32-bit struct page.
+#
+config SPLIT_PTLOCK_CPUS
+ int
+ default "4096" if ARM && !CPU_CACHE_VIPT
+ default "4096" if PARISC && DEBUG_SPINLOCK && !64BIT
+ default "4"