148 lines
4.7 KiB
Plaintext
148 lines
4.7 KiB
Plaintext
config SELECT_MEMORY_MODEL
|
|
def_bool y
|
|
depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
|
|
|
|
choice
|
|
prompt "Memory model"
|
|
depends on SELECT_MEMORY_MODEL
|
|
default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
|
|
default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
|
|
default FLATMEM_MANUAL
|
|
|
|
config FLATMEM_MANUAL
|
|
bool "Flat Memory"
|
|
depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
|
|
help
|
|
This option allows you to change some of the ways that
|
|
Linux manages its memory internally. Most users will
|
|
only have one option here: FLATMEM. This is normal
|
|
and a correct option.
|
|
|
|
Some users of more advanced features like NUMA and
|
|
memory hotplug may have different options here.
|
|
DISCONTIGMEM is an more mature, better tested system,
|
|
but is incompatible with memory hotplug and may suffer
|
|
decreased performance over SPARSEMEM. If unsure between
|
|
"Sparse Memory" and "Discontiguous Memory", choose
|
|
"Discontiguous Memory".
|
|
|
|
If unsure, choose this option (Flat Memory) over any other.
|
|
|
|
config DISCONTIGMEM_MANUAL
|
|
bool "Discontiguous Memory"
|
|
depends on ARCH_DISCONTIGMEM_ENABLE
|
|
help
|
|
This option provides enhanced support for discontiguous
|
|
memory systems, over FLATMEM. These systems have holes
|
|
in their physical address spaces, and this option provides
|
|
more efficient handling of these holes. However, the vast
|
|
majority of hardware has quite flat address spaces, and
|
|
can have degraded performance from extra overhead that
|
|
this option imposes.
|
|
|
|
Many NUMA configurations will have this as the only option.
|
|
|
|
If unsure, choose "Flat Memory" over this option.
|
|
|
|
config SPARSEMEM_MANUAL
|
|
bool "Sparse Memory"
|
|
depends on ARCH_SPARSEMEM_ENABLE
|
|
help
|
|
This will be the only option for some systems, including
|
|
memory hotplug systems. This is normal.
|
|
|
|
For many other systems, this will be an alternative to
|
|
"Discontiguous Memory". This option provides some potential
|
|
performance benefits, along with decreased code complexity,
|
|
but it is newer, and more experimental.
|
|
|
|
If unsure, choose "Discontiguous Memory" or "Flat Memory"
|
|
over this option.
|
|
|
|
endchoice
|
|
|
|
config DISCONTIGMEM
|
|
def_bool y
|
|
depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
|
|
|
|
config SPARSEMEM
|
|
def_bool y
|
|
depends on SPARSEMEM_MANUAL
|
|
|
|
config FLATMEM
|
|
def_bool y
|
|
depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
|
|
|
|
config FLAT_NODE_MEM_MAP
|
|
def_bool y
|
|
depends on !SPARSEMEM
|
|
|
|
#
|
|
# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
|
|
# to represent different areas of memory. This variable allows
|
|
# those dependencies to exist individually.
|
|
#
|
|
config NEED_MULTIPLE_NODES
|
|
def_bool y
|
|
depends on DISCONTIGMEM || NUMA
|
|
|
|
config HAVE_MEMORY_PRESENT
|
|
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 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 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
|
|
#
|
|
config SPLIT_PTLOCK_CPUS
|
|
int
|
|
default "4096" if ARM && !CPU_CACHE_VIPT
|
|
default "4096" if PARISC && !PA20
|
|
default "4"
|
|
|
|
#
|
|
# support for page migration
|
|
#
|
|
config MIGRATION
|
|
bool "Page migration"
|
|
def_bool y if NUMA || SPARSEMEM || DISCONTIGMEM
|
|
depends on SWAP
|
|
help
|
|
Allows the migration of the physical location of pages of processes
|
|
while the virtual addresses are not changed. This is useful for
|
|
example on NUMA systems to put pages nearer to the processors accessing
|
|
the page.
|