config SPARSEMEM
def_bool y
- depends on SPARSEMEM_MANUAL
+ depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
config FLATMEM
def_bool y
config MEMORY_HOTPLUG
bool "Allow for memory hot-add"
depends on SPARSEMEM || X86_64_ACPI_NUMA
- depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG
- depends on (IA64 || X86 || PPC64 || SUPERH || S390)
-
-comment "Memory hotplug is currently incompatible with Software Suspend"
- depends on SPARSEMEM && HOTPLUG && HIBERNATION
+ depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
+ depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
config MEMORY_HOTPLUG_SPARSE
def_bool y
#
config PAGEFLAGS_EXTENDED
def_bool y
- depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM
+ depends on 64BIT || SPARSEMEM_VMEMMAP || !SPARSEMEM
# Heavily threaded applications may benefit from splitting the mm-wide
# page_table_lock, so that faults on different parts of the user address
# 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.
+# DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page.
#
config SPLIT_PTLOCK_CPUS
int
- default "4096" if ARM && !CPU_CACHE_VIPT
- default "4096" if PARISC && !PA20
+ default "999999" if ARM && !CPU_CACHE_VIPT
+ default "999999" if PARISC && !PA20
+ default "999999" if DEBUG_SPINLOCK || DEBUG_LOCK_ALLOC
default "4"
#
example on NUMA systems to put pages nearer to the processors accessing
the page.
-config RESOURCES_64BIT
- bool "64 bit Memory and IO resources (EXPERIMENTAL)" if (!64BIT && EXPERIMENTAL)
- default 64BIT
- help
- This option allows memory and IO resources to be 64 bit.
+config PHYS_ADDR_T_64BIT
+ def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
config ZONE_DMA_FLAG
int
config MMU_NOTIFIER
bool
+
+config KSM
+ bool "Enable KSM for page merging"
+ depends on MMU
+ help
+ Enable Kernel Samepage Merging: KSM periodically scans those areas
+ of an application's address space that an app has advised may be
+ mergeable. When it finds pages of identical content, it replaces
+ the many instances by a single page with that content, so
+ saving memory until one or another app needs to modify the content.
+ Recommended for use with KVM, or with other duplicative applications.
+ See Documentation/vm/ksm.txt for more information: KSM is inactive
+ until a program has madvised that an area is MADV_MERGEABLE, and
+ root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
+
+config DEFAULT_MMAP_MIN_ADDR
+ int "Low address space to protect from user allocation"
+ depends on MMU
+ default 4096
+ help
+ This is the portion of low virtual memory which should be protected
+ from userspace allocation. Keeping a user from writing to low pages
+ can help reduce the impact of kernel NULL pointer bugs.
+
+ For most ia64, ppc64 and x86 users with lots of address space
+ a value of 65536 is reasonable and should cause no problems.
+ On arm and other archs it should not be higher than 32768.
+ Programs which use vm86 functionality or have some need to map
+ this low address space will need CAP_SYS_RAWIO or disable this
+ protection by setting the value to 0.
+
+ This value can be changed after boot using the
+ /proc/sys/vm/mmap_min_addr tunable.
+
+config ARCH_SUPPORTS_MEMORY_FAILURE
+ bool
+
+config MEMORY_FAILURE
+ depends on MMU
+ depends on ARCH_SUPPORTS_MEMORY_FAILURE
+ bool "Enable recovery from hardware memory errors"
+ help
+ Enables code to recover from some memory failures on systems
+ with MCA recovery. This allows a system to continue running
+ even when some of its memory has uncorrected errors. This requires
+ special hardware support and typically ECC memory.
+
+config HWPOISON_INJECT
+ tristate "HWPoison pages injector"
+ depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
+ select PROC_PAGE_MONITOR
+
+config NOMMU_INITIAL_TRIM_EXCESS
+ int "Turn on mmap() excess space trimming before booting"
+ depends on !MMU
+ default 1
+ help
+ The NOMMU mmap() frequently needs to allocate large contiguous chunks
+ of memory on which to store mappings, but it can only ask the system
+ allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
+ more than it requires. To deal with this, mmap() is able to trim off
+ the excess and return it to the allocator.
+
+ If trimming is enabled, the excess is trimmed off and returned to the
+ system allocator, which can cause extra fragmentation, particularly
+ if there are a lot of transient processes.
+
+ If trimming is disabled, the excess is kept, but not used, which for
+ long-term mappings means that the space is wasted.
+
+ Trimming can be dynamically controlled through a sysctl option
+ (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of
+ excess pages there must be before trimming should occur, or zero if
+ no trimming is to occur.
+
+ This option specifies the initial value of this option. The default
+ of 1 says that all excess pages should be trimmed.
+
+ See Documentation/nommu-mmap.txt for more information.
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