| Message ID | 20210819195533.211756-1-hannes@cmpxchg.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/4] mm: Kconfig: move swap and slab config options to the MM section | expand |
On 8/19/21 21:55, Johannes Weiner wrote: > These are currently under General Setup. MM seems like a better fit. Right. I've been also wondering about that occasionally. > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > init/Kconfig | 120 --------------------------------------------------- > mm/Kconfig | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 120 insertions(+), 120 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index a61c92066c2e..a2358cd5498a 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -331,23 +331,6 @@ 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 > @@ -1862,109 +1845,6 @@ 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" > - 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)" > - 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 > - 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 > diff --git a/mm/Kconfig b/mm/Kconfig > index 02d44e3420f5..894858536e7f 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -2,6 +2,126 @@ > > 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" > + 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)" > + 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 > + 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 >
diff --git a/init/Kconfig b/init/Kconfig index a61c92066c2e..a2358cd5498a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -331,23 +331,6 @@ 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 @@ -1862,109 +1845,6 @@ 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" - 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)" - 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 - 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 diff --git a/mm/Kconfig b/mm/Kconfig index 02d44e3420f5..894858536e7f 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -2,6 +2,126 @@ 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" + 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)" + 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 + 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
These are currently under General Setup. MM seems like a better fit. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> --- init/Kconfig | 120 --------------------------------------------------- mm/Kconfig | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+), 120 deletions(-)