mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 00:04:15 +08:00
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 <hannes@cmpxchg.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
parent
39799b6409
commit
7b42f1041c
123
init/Kconfig
123
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
|
||||
|
123
mm/Kconfig
123
mm/Kconfig
@ -2,6 +2,129 @@
|
||||
|
||||
menu "Memory Management options"
|
||||
|
||||
#
|
||||
# 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.
|
||||
|
||||
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 SELECT_MEMORY_MODEL
|
||||
def_bool y
|
||||
depends on ARCH_SELECT_MEMORY_MODEL
|
||||
|
Loading…
Reference in New Issue
Block a user