X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2FKconfig;h=c948d4ca8bde0dc0d73ba1c40b984d395a73b4d8;hb=264ef8a904943ed7d0b04fa958894d7a5c2b2c61;hp=b53427ad30a34618e6c8da34ffcc540a581de552;hpb=71aa653c6bfa6743d838342105ebc067145394e4;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/Kconfig b/mm/Kconfig index b53427a..c948d4c 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -128,11 +128,11 @@ config SPARSEMEM_VMEMMAP 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 HOTPLUG && !(HIBERNATION && !S390) && 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 SPARSEMEM && HOTPLUG && HIBERNATION && !S390 config MEMORY_HOTPLUG_SPARSE def_bool y @@ -203,23 +203,60 @@ config VIRT_TO_BUS def_bool y depends on !ARCH_NO_VIRT_TO_BUS -config UNEVICTABLE_LRU - bool "Add LRU list to track non-evictable pages" - default y - help - Keeps unevictable pages off of the active and inactive pageout - lists, so kswapd will not waste CPU time or have its balancing - algorithms thrown off by scanning these pages. Selecting this - will use one page flag and increase the code size a little, - say Y unless you know what you are doing. - config HAVE_MLOCK bool default y if MMU=y config HAVE_MLOCKED_PAGE_BIT bool - default y if HAVE_MLOCK=y && UNEVICTABLE_LRU=y + default y if HAVE_MLOCK=y config MMU_NOTIFIER bool + +config DEFAULT_MMAP_MIN_ADDR + int "Low address space to protect from user allocation" + 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 would either need additional + permissions from either the LSM or the capabilities module or have + this protection disabled. + + This value can be changed after boot using the + /proc/sys/vm/mmap_min_addr tunable. + + +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.