From 7b42f1041c98f5d7da74da8d1653a4b2c380e49d Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 19 May 2022 14:08:53 -0700 Subject: mm: Kconfig: move swap and slab config options to the MM section These are currently under General Setup. MM seems like a better fit. Link: https://lkml.kernel.org/r/20220510152847.230957-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Cc: Dan Streetman Cc: Michal Hocko Cc: Minchan Kim Cc: Roman Gushchin Cc: Seth Jennings Cc: Shakeel Butt Signed-off-by: Andrew Morton --- init/Kconfig | 123 ----------------------------------------------------------- 1 file changed, 123 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b062cd745de6..1d2ecd227f4b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -352,23 +352,6 @@ config DEFAULT_HOSTNAME but you may wish to use a different default here to make a minimal system more usable with less configuration. -# -# For some reason microblaze and nios2 hard code SWAP=n. Hopefully we can -# add proper SWAP support to them, in which case this can be remove. -# -config ARCH_NO_SWAP - bool - -config SWAP - bool "Support for paging of anonymous memory (swap)" - depends on MMU && BLOCK && !ARCH_NO_SWAP - default y - help - This option allows you to choose whether you want to have support - for so called swap devices or swap files in your kernel that are - used to provide more virtual memory than the actual RAM present - in your computer. If unsure say Y. - config SYSVIPC bool "System V IPC" help @@ -1876,112 +1859,6 @@ config COMPAT_BRK On non-ancient distros (post-2000 ones) N is usually a safe choice. -choice - prompt "Choose SLAB allocator" - default SLUB - help - This option allows to select a slab allocator. - -config SLAB - bool "SLAB" - depends on !PREEMPT_RT - select HAVE_HARDENED_USERCOPY_ALLOCATOR - help - The regular slab allocator that is established and known to work - well in all environments. It organizes cache hot objects in - per cpu and per node queues. - -config SLUB - bool "SLUB (Unqueued Allocator)" - select HAVE_HARDENED_USERCOPY_ALLOCATOR - help - SLUB is a slab allocator that minimizes cache line usage - instead of managing queues of cached objects (SLAB approach). - Per cpu caching is realized using slabs of objects instead - of queues of objects. SLUB can use memory efficiently - and has enhanced diagnostics. SLUB is the default choice for - a slab allocator. - -config SLOB - depends on EXPERT - bool "SLOB (Simple Allocator)" - depends on !PREEMPT_RT - help - SLOB replaces the stock allocator with a drastically simpler - allocator. SLOB is generally more space efficient but - does not perform as well on large systems. - -endchoice - -config SLAB_MERGE_DEFAULT - bool "Allow slab caches to be merged" - default y - depends on SLAB || SLUB - help - For reduced kernel memory fragmentation, slab caches can be - merged when they share the same size and other characteristics. - This carries a risk of kernel heap overflows being able to - overwrite objects from merged caches (and more easily control - cache layout), which makes such heap attacks easier to exploit - by attackers. By keeping caches unmerged, these kinds of exploits - can usually only damage objects in the same cache. To disable - merging at runtime, "slab_nomerge" can be passed on the kernel - command line. - -config SLAB_FREELIST_RANDOM - bool "Randomize slab freelist" - depends on SLAB || SLUB - help - Randomizes the freelist order used on creating new pages. This - security feature reduces the predictability of the kernel slab - allocator against heap overflows. - -config SLAB_FREELIST_HARDENED - bool "Harden slab freelist metadata" - depends on SLAB || SLUB - help - Many kernel heap attacks try to target slab cache metadata and - other infrastructure. This options makes minor performance - sacrifices to harden the kernel slab allocator against common - freelist exploit methods. Some slab implementations have more - sanity-checking than others. This option is most effective with - CONFIG_SLUB. - -config SHUFFLE_PAGE_ALLOCATOR - bool "Page allocator randomization" - default SLAB_FREELIST_RANDOM && ACPI_NUMA - help - Randomization of the page allocator improves the average - utilization of a direct-mapped memory-side-cache. See section - 5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI - 6.2a specification for an example of how a platform advertises - the presence of a memory-side-cache. There are also incidental - security benefits as it reduces the predictability of page - allocations to compliment SLAB_FREELIST_RANDOM, but the - default granularity of shuffling on the "MAX_ORDER - 1" i.e, - 10th order of pages is selected based on cache utilization - benefits on x86. - - While the randomization improves cache utilization it may - negatively impact workloads on platforms without a cache. For - this reason, by default, the randomization is enabled only - after runtime detection of a direct-mapped memory-side-cache. - Otherwise, the randomization may be force enabled with the - 'page_alloc.shuffle' kernel command line parameter. - - Say Y if unsure. - -config SLUB_CPU_PARTIAL - default y - depends on SLUB && SMP - bool "SLUB per cpu partial cache" - help - Per cpu partial caches accelerate objects allocation and freeing - that is local to a processor at the price of more indeterminism - in the latency of the free. On overflow these caches will be cleared - which requires the taking of locks that may cause latency spikes. - Typically one would choose no for a realtime system. - config MMAP_ALLOW_UNINITIALIZED bool "Allow mmapped anonymous memory to be uninitialized" depends on EXPERT && !MMU -- cgit v1.2.3-58-ga151