Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and
everything in Kconfig files and mm/Makefile that depends on those. Since
SLUB is the only remaining allocator, remove the allocator choice, make
CONFIG_SLUB a "def_bool y" for now and remove all explicit dependencies
on SLUB or SLAB as it's now always enabled. Make every option's verbose
name and description refer to "the slab allocator" without refering to
the specific implementation. Do not rename the CONFIG_ option names yet.
Everything under #ifdef CONFIG_SLAB, and mm/slab.c is now dead code, all
code under #ifdef CONFIG_SLUB is now always compiled.
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Christoph Lameter <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>
---
arch/arm64/Kconfig | 2 +-
arch/s390/Kconfig | 2 +-
arch/x86/Kconfig | 2 +-
lib/Kconfig.debug | 1 -
lib/Kconfig.kasan | 11 +++------
lib/Kconfig.kfence | 2 +-
lib/Kconfig.kmsan | 2 +-
mm/Kconfig | 68 ++++++++++++------------------------------------------
mm/Kconfig.debug | 16 ++++---------
mm/Makefile | 6 +----
10 files changed, 28 insertions(+), 84 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7b071a00425d..325b7140b576 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -154,7 +154,7 @@ config ARM64
select HAVE_MOVE_PUD
select HAVE_PCI
select HAVE_ACPI_APEI if (ACPI && EFI)
- select HAVE_ALIGNED_STRUCT_PAGE if SLUB
+ select HAVE_ALIGNED_STRUCT_PAGE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_BITREVERSE
select HAVE_ARCH_COMPILER_H
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 3bec98d20283..afa42a6f2e09 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -146,7 +146,7 @@ config S390
select GENERIC_TIME_VSYSCALL
select GENERIC_VDSO_TIME_NS
select GENERIC_IOREMAP if PCI
- select HAVE_ALIGNED_STRUCT_PAGE if SLUB
+ select HAVE_ALIGNED_STRUCT_PAGE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3762f41bb092..3f460f334d4e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -169,7 +169,7 @@ config X86
select HAS_IOPORT
select HAVE_ACPI_APEI if ACPI
select HAVE_ACPI_APEI_NMI if ACPI
- select HAVE_ALIGNED_STRUCT_PAGE if SLUB
+ select HAVE_ALIGNED_STRUCT_PAGE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
select HAVE_ARCH_HUGE_VMALLOC if X86_64
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cc7d53d9dc01..e1765face106 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1985,7 +1985,6 @@ config FAULT_INJECTION
config FAILSLAB
bool "Fault-injection capability for kmalloc"
depends on FAULT_INJECTION
- depends on SLAB || SLUB
help
Provide fault-injection capability for kmalloc.
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index fdca89c05745..97e1fdbb5910 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -37,7 +37,7 @@ menuconfig KASAN
(HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)) && \
CC_HAS_WORKING_NOSANITIZE_ADDRESS) || \
HAVE_ARCH_KASAN_HW_TAGS
- depends on (SLUB && SYSFS && !SLUB_TINY) || (SLAB && !DEBUG_SLAB)
+ depends on SYSFS && !SLUB_TINY
select STACKDEPOT_ALWAYS_INIT
help
Enables KASAN (Kernel Address Sanitizer) - a dynamic memory safety
@@ -78,7 +78,7 @@ config KASAN_GENERIC
bool "Generic KASAN"
depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC
depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
- select SLUB_DEBUG if SLUB
+ select SLUB_DEBUG
select CONSTRUCTORS
help
Enables Generic KASAN.
@@ -89,13 +89,11 @@ config KASAN_GENERIC
overhead of ~50% for dynamic allocations.
The performance slowdown is ~x3.
- (Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
-
config KASAN_SW_TAGS
bool "Software Tag-Based KASAN"
depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS
depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
- select SLUB_DEBUG if SLUB
+ select SLUB_DEBUG
select CONSTRUCTORS
help
Enables Software Tag-Based KASAN.
@@ -110,12 +108,9 @@ config KASAN_SW_TAGS
May potentially introduce problems related to pointer casting and
comparison, as it embeds a tag into the top byte of each pointer.
- (Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
-
config KASAN_HW_TAGS
bool "Hardware Tag-Based KASAN"
depends on HAVE_ARCH_KASAN_HW_TAGS
- depends on SLUB
help
Enables Hardware Tag-Based KASAN.
diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
index 459dda9ef619..6fbbebec683a 100644
--- a/lib/Kconfig.kfence
+++ b/lib/Kconfig.kfence
@@ -5,7 +5,7 @@ config HAVE_ARCH_KFENCE
menuconfig KFENCE
bool "KFENCE: low-overhead sampling-based memory safety error detector"
- depends on HAVE_ARCH_KFENCE && (SLAB || SLUB)
+ depends on HAVE_ARCH_KFENCE
select STACKTRACE
select IRQ_WORK
help
diff --git a/lib/Kconfig.kmsan b/lib/Kconfig.kmsan
index ef2c8f256c57..0541d7b079cc 100644
--- a/lib/Kconfig.kmsan
+++ b/lib/Kconfig.kmsan
@@ -11,7 +11,7 @@ config HAVE_KMSAN_COMPILER
config KMSAN
bool "KMSAN: detector of uninitialized values use"
depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
- depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN
+ depends on DEBUG_KERNEL && !KASAN && !KCSAN
depends on !PREEMPT_RT
select STACKDEPOT
select STACKDEPOT_ALWAYS_INIT
diff --git a/mm/Kconfig b/mm/Kconfig
index 89971a894b60..4636870499bb 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -226,52 +226,17 @@ config ZSMALLOC_CHAIN_SIZE
For more information, see zsmalloc documentation.
-menu "SLAB allocator options"
-
-choice
- prompt "Choose SLAB allocator"
- default SLUB
- help
- This option allows to select a slab allocator.
-
-config SLAB_DEPRECATED
- bool "SLAB (DEPRECATED)"
- depends on !PREEMPT_RT
- help
- Deprecated and scheduled for removal in a few cycles. Replaced by
- SLUB.
-
- If you cannot migrate to SLUB, please contact [email protected]
- and the people listed in the SLAB ALLOCATOR section of MAINTAINERS
- file, explaining why.
-
- 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.
+menu "Slab allocator options"
config SLUB
- bool "SLUB (Unqueued 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.
-
-endchoice
-
-config SLAB
- bool
- default y
- depends on SLAB_DEPRECATED
+ def_bool y
config SLUB_TINY
- bool "Configure SLUB for minimal memory footprint"
- depends on SLUB && EXPERT
+ bool "Configure for minimal memory footprint"
+ depends on EXPERT
select SLAB_MERGE_DEFAULT
help
- Configures the SLUB allocator in a way to achieve minimal memory
+ Configures the slab allocator in a way to achieve minimal memory
footprint, sacrificing scalability, debugging and other features.
This is intended only for the smallest system that had used the
SLOB allocator and is not recommended for systems with more than
@@ -282,7 +247,6 @@ config SLUB_TINY
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.
@@ -296,7 +260,7 @@ config SLAB_MERGE_DEFAULT
config SLAB_FREELIST_RANDOM
bool "Randomize slab freelist"
- depends on SLAB || (SLUB && !SLUB_TINY)
+ depends on !SLUB_TINY
help
Randomizes the freelist order used on creating new pages. This
security feature reduces the predictability of the kernel slab
@@ -304,21 +268,19 @@ config SLAB_FREELIST_RANDOM
config SLAB_FREELIST_HARDENED
bool "Harden slab freelist metadata"
- depends on SLAB || (SLUB && !SLUB_TINY)
+ depends on !SLUB_TINY
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.
+ freelist exploit methods.
config SLUB_STATS
default n
- bool "Enable SLUB performance statistics"
- depends on SLUB && SYSFS && !SLUB_TINY
+ bool "Enable performance statistics"
+ depends on SYSFS && !SLUB_TINY
help
- SLUB statistics are useful to debug SLUBs allocation behavior in
+ The statistics are useful to debug slab allocation behavior in
order find ways to optimize the allocator. This should never be
enabled for production use since keeping statistics slows down
the allocator by a few percentage points. The slabinfo command
@@ -328,8 +290,8 @@ config SLUB_STATS
config SLUB_CPU_PARTIAL
default y
- depends on SLUB && SMP && !SLUB_TINY
- bool "SLUB per cpu partial cache"
+ depends on SMP && !SLUB_TINY
+ bool "Enable per cpu partial caches"
help
Per cpu partial caches accelerate objects allocation and freeing
that is local to a processor at the price of more indeterminism
@@ -339,7 +301,7 @@ config SLUB_CPU_PARTIAL
config RANDOM_KMALLOC_CACHES
default n
- depends on SLUB && !SLUB_TINY
+ depends on !SLUB_TINY
bool "Randomize slab caches for normal kmalloc"
help
A hardening feature that creates multiple copies of slab caches for
@@ -354,7 +316,7 @@ config RANDOM_KMALLOC_CACHES
limited degree of memory and CPU overhead that relates to hardware and
system workload.
-endmenu # SLAB allocator options
+endmenu # Slab allocator options
config SHUFFLE_PAGE_ALLOCATOR
bool "Page allocator randomization"
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 018a5bd2f576..321ab379994f 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -45,18 +45,10 @@ config DEBUG_PAGEALLOC_ENABLE_DEFAULT
Enable debug page memory allocations by default? This value
can be overridden by debug_pagealloc=off|on.
-config DEBUG_SLAB
- bool "Debug slab memory allocations"
- depends on DEBUG_KERNEL && SLAB
- help
- Say Y here to have the kernel do limited verification on memory
- allocation as well as poisoning memory on free to catch use of freed
- memory. This can make kmalloc/kfree-intensive workloads much slower.
-
config SLUB_DEBUG
default y
bool "Enable SLUB debugging support" if EXPERT
- depends on SLUB && SYSFS && !SLUB_TINY
+ depends on SYSFS && !SLUB_TINY
select STACKDEPOT if STACKTRACE_SUPPORT
help
SLUB has extensive debug support features. Disabling these can
@@ -66,7 +58,7 @@ config SLUB_DEBUG
config SLUB_DEBUG_ON
bool "SLUB debugging on by default"
- depends on SLUB && SLUB_DEBUG
+ depends on SLUB_DEBUG
select STACKDEPOT_ALWAYS_INIT if STACKTRACE_SUPPORT
default n
help
@@ -231,8 +223,8 @@ config DEBUG_KMEMLEAK
allocations. See Documentation/dev-tools/kmemleak.rst for more
details.
- Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
- of finding leaks due to the slab objects poisoning.
+ Enabling SLUB_DEBUG may increase the chances of finding leaks
+ due to the slab objects poisoning.
In order to access the kmemleak file, debugfs needs to be
mounted (usually at /sys/kernel/debug).
diff --git a/mm/Makefile b/mm/Makefile
index 33873c8aedb3..e4b5b75aaec9 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -4,7 +4,6 @@
#
KASAN_SANITIZE_slab_common.o := n
-KASAN_SANITIZE_slab.o := n
KASAN_SANITIZE_slub.o := n
KCSAN_SANITIZE_kmemleak.o := n
@@ -12,7 +11,6 @@ KCSAN_SANITIZE_kmemleak.o := n
# the same word but accesses to different bits of that word. Re-enable KCSAN
# for these when we have more consensus on what to do about them.
KCSAN_SANITIZE_slab_common.o := n
-KCSAN_SANITIZE_slab.o := n
KCSAN_SANITIZE_slub.o := n
KCSAN_SANITIZE_page_alloc.o := n
# But enable explicit instrumentation for memory barriers.
@@ -22,7 +20,6 @@ KCSAN_INSTRUMENT_BARRIERS := y
# flaky coverage that is not a function of syscall inputs. E.g. slab is out of
# free pages, or a task is migrated between nodes.
KCOV_INSTRUMENT_slab_common.o := n
-KCOV_INSTRUMENT_slab.o := n
KCOV_INSTRUMENT_slub.o := n
KCOV_INSTRUMENT_page_alloc.o := n
KCOV_INSTRUMENT_debug-pagealloc.o := n
@@ -66,6 +63,7 @@ obj-y += page-alloc.o
obj-y += init-mm.o
obj-y += memblock.o
obj-y += $(memory-hotplug-y)
+obj-y += slub.o
ifdef CONFIG_MMU
obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o
@@ -82,8 +80,6 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
obj-$(CONFIG_KSM) += ksm.o
obj-$(CONFIG_PAGE_POISONING) += page_poison.o
-obj-$(CONFIG_SLAB) += slab.o
-obj-$(CONFIG_SLUB) += slub.o
obj-$(CONFIG_KASAN) += kasan/
obj-$(CONFIG_KFENCE) += kfence/
obj-$(CONFIG_KMSAN) += kmsan/
--
2.42.1
On Mon, Nov 20, 2023 at 07:34:13PM +0100, Vlastimil Babka wrote:
> Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and
> everything in Kconfig files and mm/Makefile that depends on those. Since
> SLUB is the only remaining allocator, remove the allocator choice, make
> CONFIG_SLUB a "def_bool y" for now and remove all explicit dependencies
> on SLUB or SLAB as it's now always enabled. Make every option's verbose
> name and description refer to "the slab allocator" without refering to
> the specific implementation. Do not rename the CONFIG_ option names yet.
>
> Everything under #ifdef CONFIG_SLAB, and mm/slab.c is now dead code, all
> code under #ifdef CONFIG_SLUB is now always compiled.
>
> Reviewed-by: Kees Cook <[email protected]>
> Reviewed-by: Christoph Lameter <[email protected]>
> Signed-off-by: Vlastimil Babka <[email protected]>
> ---
> arch/arm64/Kconfig | 2 +-
> arch/s390/Kconfig | 2 +-
> arch/x86/Kconfig | 2 +-
> lib/Kconfig.debug | 1 -
> lib/Kconfig.kasan | 11 +++------
> lib/Kconfig.kfence | 2 +-
> lib/Kconfig.kmsan | 2 +-
> mm/Kconfig | 68 ++++++++++++------------------------------------------
> mm/Kconfig.debug | 16 ++++---------
> mm/Makefile | 6 +----
> 10 files changed, 28 insertions(+), 84 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7b071a00425d..325b7140b576 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -154,7 +154,7 @@ config ARM64
> select HAVE_MOVE_PUD
> select HAVE_PCI
> select HAVE_ACPI_APEI if (ACPI && EFI)
> - select HAVE_ALIGNED_STRUCT_PAGE if SLUB
> + select HAVE_ALIGNED_STRUCT_PAGE
> select HAVE_ARCH_AUDITSYSCALL
> select HAVE_ARCH_BITREVERSE
> select HAVE_ARCH_COMPILER_H
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index 3bec98d20283..afa42a6f2e09 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -146,7 +146,7 @@ config S390
> select GENERIC_TIME_VSYSCALL
> select GENERIC_VDSO_TIME_NS
> select GENERIC_IOREMAP if PCI
> - select HAVE_ALIGNED_STRUCT_PAGE if SLUB
> + select HAVE_ALIGNED_STRUCT_PAGE
> select HAVE_ARCH_AUDITSYSCALL
> select HAVE_ARCH_JUMP_LABEL
> select HAVE_ARCH_JUMP_LABEL_RELATIVE
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 3762f41bb092..3f460f334d4e 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -169,7 +169,7 @@ config X86
> select HAS_IOPORT
> select HAVE_ACPI_APEI if ACPI
> select HAVE_ACPI_APEI_NMI if ACPI
> - select HAVE_ALIGNED_STRUCT_PAGE if SLUB
> + select HAVE_ALIGNED_STRUCT_PAGE
> select HAVE_ARCH_AUDITSYSCALL
> select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
> select HAVE_ARCH_HUGE_VMALLOC if X86_64
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index cc7d53d9dc01..e1765face106 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1985,7 +1985,6 @@ config FAULT_INJECTION
> config FAILSLAB
> bool "Fault-injection capability for kmalloc"
> depends on FAULT_INJECTION
> - depends on SLAB || SLUB
> help
> Provide fault-injection capability for kmalloc.
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index fdca89c05745..97e1fdbb5910 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -37,7 +37,7 @@ menuconfig KASAN
> (HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)) && \
> CC_HAS_WORKING_NOSANITIZE_ADDRESS) || \
> HAVE_ARCH_KASAN_HW_TAGS
> - depends on (SLUB && SYSFS && !SLUB_TINY) || (SLAB && !DEBUG_SLAB)
> + depends on SYSFS && !SLUB_TINY
> select STACKDEPOT_ALWAYS_INIT
> help
> Enables KASAN (Kernel Address Sanitizer) - a dynamic memory safety
> @@ -78,7 +78,7 @@ config KASAN_GENERIC
> bool "Generic KASAN"
> depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC
> depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
> - select SLUB_DEBUG if SLUB
> + select SLUB_DEBUG
> select CONSTRUCTORS
> help
> Enables Generic KASAN.
> @@ -89,13 +89,11 @@ config KASAN_GENERIC
> overhead of ~50% for dynamic allocations.
> The performance slowdown is ~x3.
>
> - (Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
> -
> config KASAN_SW_TAGS
> bool "Software Tag-Based KASAN"
> depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS
> depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS
> - select SLUB_DEBUG if SLUB
> + select SLUB_DEBUG
> select CONSTRUCTORS
> help
> Enables Software Tag-Based KASAN.
> @@ -110,12 +108,9 @@ config KASAN_SW_TAGS
> May potentially introduce problems related to pointer casting and
> comparison, as it embeds a tag into the top byte of each pointer.
>
> - (Incompatible with CONFIG_DEBUG_SLAB: the kernel does not boot.)
> -
> config KASAN_HW_TAGS
> bool "Hardware Tag-Based KASAN"
> depends on HAVE_ARCH_KASAN_HW_TAGS
> - depends on SLUB
> help
> Enables Hardware Tag-Based KASAN.
>
> diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
> index 459dda9ef619..6fbbebec683a 100644
> --- a/lib/Kconfig.kfence
> +++ b/lib/Kconfig.kfence
> @@ -5,7 +5,7 @@ config HAVE_ARCH_KFENCE
>
> menuconfig KFENCE
> bool "KFENCE: low-overhead sampling-based memory safety error detector"
> - depends on HAVE_ARCH_KFENCE && (SLAB || SLUB)
> + depends on HAVE_ARCH_KFENCE
> select STACKTRACE
> select IRQ_WORK
> help
> diff --git a/lib/Kconfig.kmsan b/lib/Kconfig.kmsan
> index ef2c8f256c57..0541d7b079cc 100644
> --- a/lib/Kconfig.kmsan
> +++ b/lib/Kconfig.kmsan
> @@ -11,7 +11,7 @@ config HAVE_KMSAN_COMPILER
> config KMSAN
> bool "KMSAN: detector of uninitialized values use"
> depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER
> - depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN
> + depends on DEBUG_KERNEL && !KASAN && !KCSAN
> depends on !PREEMPT_RT
> select STACKDEPOT
> select STACKDEPOT_ALWAYS_INIT
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 89971a894b60..4636870499bb 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -226,52 +226,17 @@ config ZSMALLOC_CHAIN_SIZE
>
> For more information, see zsmalloc documentation.
>
> -menu "SLAB allocator options"
> -
> -choice
> - prompt "Choose SLAB allocator"
> - default SLUB
> - help
> - This option allows to select a slab allocator.
> -
> -config SLAB_DEPRECATED
> - bool "SLAB (DEPRECATED)"
> - depends on !PREEMPT_RT
> - help
> - Deprecated and scheduled for removal in a few cycles. Replaced by
> - SLUB.
> -
> - If you cannot migrate to SLUB, please contact [email protected]
> - and the people listed in the SLAB ALLOCATOR section of MAINTAINERS
> - file, explaining why.
> -
> - 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.
> +menu "Slab allocator options"
>
> config SLUB
> - bool "SLUB (Unqueued 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.
> -
> -endchoice
> -
> -config SLAB
> - bool
> - default y
> - depends on SLAB_DEPRECATED
> + def_bool y
>
> config SLUB_TINY
> - bool "Configure SLUB for minimal memory footprint"
> - depends on SLUB && EXPERT
> + bool "Configure for minimal memory footprint"
> + depends on EXPERT
> select SLAB_MERGE_DEFAULT
> help
> - Configures the SLUB allocator in a way to achieve minimal memory
> + Configures the slab allocator in a way to achieve minimal memory
> footprint, sacrificing scalability, debugging and other features.
> This is intended only for the smallest system that had used the
> SLOB allocator and is not recommended for systems with more than
> @@ -282,7 +247,6 @@ config SLUB_TINY
> 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.
> @@ -296,7 +260,7 @@ config SLAB_MERGE_DEFAULT
>
> config SLAB_FREELIST_RANDOM
> bool "Randomize slab freelist"
> - depends on SLAB || (SLUB && !SLUB_TINY)
> + depends on !SLUB_TINY
> help
> Randomizes the freelist order used on creating new pages. This
> security feature reduces the predictability of the kernel slab
> @@ -304,21 +268,19 @@ config SLAB_FREELIST_RANDOM
>
> config SLAB_FREELIST_HARDENED
> bool "Harden slab freelist metadata"
> - depends on SLAB || (SLUB && !SLUB_TINY)
> + depends on !SLUB_TINY
> 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.
> + freelist exploit methods.
>
> config SLUB_STATS
> default n
> - bool "Enable SLUB performance statistics"
> - depends on SLUB && SYSFS && !SLUB_TINY
> + bool "Enable performance statistics"
> + depends on SYSFS && !SLUB_TINY
> help
> - SLUB statistics are useful to debug SLUBs allocation behavior in
> + The statistics are useful to debug slab allocation behavior in
> order find ways to optimize the allocator. This should never be
> enabled for production use since keeping statistics slows down
> the allocator by a few percentage points. The slabinfo command
> @@ -328,8 +290,8 @@ config SLUB_STATS
>
> config SLUB_CPU_PARTIAL
> default y
> - depends on SLUB && SMP && !SLUB_TINY
> - bool "SLUB per cpu partial cache"
> + depends on SMP && !SLUB_TINY
> + bool "Enable per cpu partial caches"
> help
> Per cpu partial caches accelerate objects allocation and freeing
> that is local to a processor at the price of more indeterminism
> @@ -339,7 +301,7 @@ config SLUB_CPU_PARTIAL
>
> config RANDOM_KMALLOC_CACHES
> default n
> - depends on SLUB && !SLUB_TINY
> + depends on !SLUB_TINY
> bool "Randomize slab caches for normal kmalloc"
> help
> A hardening feature that creates multiple copies of slab caches for
> @@ -354,7 +316,7 @@ config RANDOM_KMALLOC_CACHES
> limited degree of memory and CPU overhead that relates to hardware and
> system workload.
>
> -endmenu # SLAB allocator options
> +endmenu # Slab allocator options
>
> config SHUFFLE_PAGE_ALLOCATOR
> bool "Page allocator randomization"
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 018a5bd2f576..321ab379994f 100644
> --- a/mm/Kconfig.debug
> +++ b/mm/Kconfig.debug
> @@ -45,18 +45,10 @@ config DEBUG_PAGEALLOC_ENABLE_DEFAULT
> Enable debug page memory allocations by default? This value
> can be overridden by debug_pagealloc=off|on.
>
> -config DEBUG_SLAB
> - bool "Debug slab memory allocations"
> - depends on DEBUG_KERNEL && SLAB
> - help
> - Say Y here to have the kernel do limited verification on memory
> - allocation as well as poisoning memory on free to catch use of freed
> - memory. This can make kmalloc/kfree-intensive workloads much slower.
> -
> config SLUB_DEBUG
> default y
> bool "Enable SLUB debugging support" if EXPERT
> - depends on SLUB && SYSFS && !SLUB_TINY
> + depends on SYSFS && !SLUB_TINY
> select STACKDEPOT if STACKTRACE_SUPPORT
> help
> SLUB has extensive debug support features. Disabling these can
> @@ -66,7 +58,7 @@ config SLUB_DEBUG
>
> config SLUB_DEBUG_ON
> bool "SLUB debugging on by default"
> - depends on SLUB && SLUB_DEBUG
> + depends on SLUB_DEBUG
> select STACKDEPOT_ALWAYS_INIT if STACKTRACE_SUPPORT
> default n
> help
> @@ -231,8 +223,8 @@ config DEBUG_KMEMLEAK
> allocations. See Documentation/dev-tools/kmemleak.rst for more
> details.
>
> - Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
> - of finding leaks due to the slab objects poisoning.
> + Enabling SLUB_DEBUG may increase the chances of finding leaks
> + due to the slab objects poisoning.
>
> In order to access the kmemleak file, debugfs needs to be
> mounted (usually at /sys/kernel/debug).
> diff --git a/mm/Makefile b/mm/Makefile
> index 33873c8aedb3..e4b5b75aaec9 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -4,7 +4,6 @@
> #
>
> KASAN_SANITIZE_slab_common.o := n
> -KASAN_SANITIZE_slab.o := n
> KASAN_SANITIZE_slub.o := n
> KCSAN_SANITIZE_kmemleak.o := n
>
> @@ -12,7 +11,6 @@ KCSAN_SANITIZE_kmemleak.o := n
> # the same word but accesses to different bits of that word. Re-enable KCSAN
> # for these when we have more consensus on what to do about them.
> KCSAN_SANITIZE_slab_common.o := n
> -KCSAN_SANITIZE_slab.o := n
> KCSAN_SANITIZE_slub.o := n
> KCSAN_SANITIZE_page_alloc.o := n
> # But enable explicit instrumentation for memory barriers.
> @@ -22,7 +20,6 @@ KCSAN_INSTRUMENT_BARRIERS := y
> # flaky coverage that is not a function of syscall inputs. E.g. slab is out of
> # free pages, or a task is migrated between nodes.
> KCOV_INSTRUMENT_slab_common.o := n
> -KCOV_INSTRUMENT_slab.o := n
> KCOV_INSTRUMENT_slub.o := n
> KCOV_INSTRUMENT_page_alloc.o := n
> KCOV_INSTRUMENT_debug-pagealloc.o := n
> @@ -66,6 +63,7 @@ obj-y += page-alloc.o
> obj-y += init-mm.o
> obj-y += memblock.o
> obj-y += $(memory-hotplug-y)
> +obj-y += slub.o
>
> ifdef CONFIG_MMU
> obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o
> @@ -82,8 +80,6 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
> obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
> obj-$(CONFIG_KSM) += ksm.o
> obj-$(CONFIG_PAGE_POISONING) += page_poison.o
> -obj-$(CONFIG_SLAB) += slab.o
> -obj-$(CONFIG_SLUB) += slub.o
> obj-$(CONFIG_KASAN) += kasan/
> obj-$(CONFIG_KFENCE) += kfence/
> obj-$(CONFIG_KMSAN) += kmsan/
Looks good to me,
Reviewed-by: Hyeonggon Yoo <[email protected]>
Nit:
- Some arch configs enables DEBUG_SLAB
- Some documentations refers to {DEBUG_,}SLAB config (i.e. "enable
DEBUG_SLAB for debugging", or "use SLUB instead of SLAB for reducing OS
jitter", ... etc)
- fs/orangefs/orangefs-kernel.h uses #if (defined CONFIG_DEBUG_SLAB)
$ git grep DEBUG_SLAB arch/
arch/arm/configs/ep93xx_defconfig:CONFIG_DEBUG_SLAB=y
arch/arm/configs/tegra_defconfig:CONFIG_DEBUG_SLAB=y
arch/microblaze/configs/mmu_defconfig:CONFIG_DEBUG_SLAB=y
$ git grep SLAB Documentation/
[... some unrelated lines removed ...]
Documentation/admin-guide/cgroup-v1/cpusets.rst:PFA_SPREAD_SLAB, and appropriately marked slab caches will allocate
Documentation/admin-guide/cgroup-v1/memory.rst: pages allocated by the SLAB or SLUB allocator are tracked. A copy
Documentation/admin-guide/kernel-per-CPU-kthreads.rst: CONFIG_SLAB=y, thus avoiding the slab allocator's periodic
Documentation/admin-guide/mm/pagemap.rst: The page is managed by the SLAB/SLUB kernel memory allocator.
Documentation/dev-tools/kasan.rst:For slab, both software KASAN modes support SLUB and SLAB allocators, while
Documentation/dev-tools/kfence.rst:of the sample interval, the next allocation through the main allocator (SLAB or
Documentation/mm/slub.rst:The basic philosophy of SLUB is very different from SLAB. SLAB
Documentation/mm/slub.rst: Sorry SLAB legacy issues)
Documentation/process/4.Coding.rst: - DEBUG_SLAB can find a variety of memory allocation and use errors; it
Documentation/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
Documentation/scsi/ChangeLog.lpfc: CONFIG_DEBUG_SLAB set).
Documentation/translations/it_IT/process/4.Coding.rst: - DEBUG_SLAB può trovare svariati errori di uso e di allocazione di memoria;
Documentation/translations/it_IT/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
Documentation/translations/ja_JP/SubmitChecklist:12: CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB,
Documentation/translations/zh_CN/dev-tools/kasan.rst:对于slab，两种软件KASAN模式都支持SLUB和SLAB分配器，而基于硬件标签的
Documentation/translations/zh_CN/process/4.Coding.rst: - DEBUG_SLAB 可以发现各种内存分配和使用错误；它应该用于大多数开发内核。
Documentation/translations/zh_CN/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
Documentation/translations/zh_TW/dev-tools/kasan.rst:對於slab，兩種軟件KASAN模式都支持SLUB和SLAB分配器，而基於硬件標籤的
Documentation/translations/zh_TW/process/4.Coding.rst: - DEBUG_SLAB 可以發現各種內存分配和使用錯誤；它應該用於大多數開發內核。
Documentation/translations/zh_TW/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
--
Hyeonggon
On 12/5/23 05:15, Hyeonggon Yoo wrote:
> On Mon, Nov 20, 2023 at 07:34:13PM +0100, Vlastimil Babka wrote:
>
> Looks good to me,
> Reviewed-by: Hyeonggon Yoo <[email protected]>
Thanks.
> Nit:
>
> - Some arch configs enables DEBUG_SLAB
> - Some documentations refers to {DEBUG_,}SLAB config (i.e. "enable
> DEBUG_SLAB for debugging", or "use SLUB instead of SLAB for reducing OS
> jitter", ... etc)
> - fs/orangefs/orangefs-kernel.h uses #if (defined CONFIG_DEBUG_SLAB)
>
> $ git grep DEBUG_SLAB arch/
> arch/arm/configs/ep93xx_defconfig:CONFIG_DEBUG_SLAB=y
> arch/arm/configs/tegra_defconfig:CONFIG_DEBUG_SLAB=y
> arch/microblaze/configs/mmu_defconfig:CONFIG_DEBUG_SLAB=y
>
> $ git grep SLAB Documentation/
>
> [... some unrelated lines removed ...]
Yep, I've wrote in the cover letter that to keep the series reasonable and
limit Ccing other subsystems on some patches, not everything is cleaned up
thoroughly, and is left for further work (some already started coming in
from others) that can be submitted to relevant subsystems.
> Documentation/admin-guide/cgroup-v1/cpusets.rst:PFA_SPREAD_SLAB, and appropriately marked slab caches will allocate
> Documentation/admin-guide/cgroup-v1/memory.rst: pages allocated by the SLAB or SLUB allocator are tracked. A copy
> Documentation/admin-guide/kernel-per-CPU-kthreads.rst: CONFIG_SLAB=y, thus avoiding the slab allocator's periodic
> Documentation/admin-guide/mm/pagemap.rst: The page is managed by the SLAB/SLUB kernel memory allocator.
> Documentation/dev-tools/kasan.rst:For slab, both software KASAN modes support SLUB and SLAB allocators, while
> Documentation/dev-tools/kfence.rst:of the sample interval, the next allocation through the main allocator (SLAB or
> Documentation/mm/slub.rst:The basic philosophy of SLUB is very different from SLAB. SLAB
> Documentation/mm/slub.rst: Sorry SLAB legacy issues)
> Documentation/process/4.Coding.rst: - DEBUG_SLAB can find a variety of memory allocation and use errors; it
> Documentation/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> Documentation/scsi/ChangeLog.lpfc: CONFIG_DEBUG_SLAB set).
> Documentation/translations/it_IT/process/4.Coding.rst: - DEBUG_SLAB può trovare svariati errori di uso e di allocazione di memoria;
> Documentation/translations/it_IT/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> Documentation/translations/ja_JP/SubmitChecklist:12: CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB,
> Documentation/translations/zh_CN/dev-tools/kasan.rst:对于slab，两种软件KASAN模式都支持SLUB和SLAB分配器，而基于硬件标签的
> Documentation/translations/zh_CN/process/4.Coding.rst: - DEBUG_SLAB 可以发现各种内存分配和使用错误；它应该用于大多数开发内核。
> Documentation/translations/zh_CN/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> Documentation/translations/zh_TW/dev-tools/kasan.rst:對於slab，兩種軟件KASAN模式都支持SLUB和SLAB分配器，而基於硬件標籤的
> Documentation/translations/zh_TW/process/4.Coding.rst: - DEBUG_SLAB 可以發現各種內存分配和使用錯誤；它應該用於大多數開發內核。
> Documentation/translations/zh_TW/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
>
> --
> Hyeonggon
On Tue, Dec 5, 2023 at 7:14 PM Vlastimil Babka <[email protected]> wrote:
>
> On 12/5/23 05:15, Hyeonggon Yoo wrote:
> > On Mon, Nov 20, 2023 at 07:34:13PM +0100, Vlastimil Babka wrote:
> >
> > Looks good to me,
> > Reviewed-by: Hyeonggon Yoo <[email protected]>
>
> Thanks.
>
> > Nit:
> >
> > - Some arch configs enables DEBUG_SLAB
> > - Some documentations refers to {DEBUG_,}SLAB config (i.e. "enable
> > DEBUG_SLAB for debugging", or "use SLUB instead of SLAB for reducing OS
> > jitter", ... etc)
> > - fs/orangefs/orangefs-kernel.h uses #if (defined CONFIG_DEBUG_SLAB)
> >
> > $ git grep DEBUG_SLAB arch/
> > arch/arm/configs/ep93xx_defconfig:CONFIG_DEBUG_SLAB=y
> > arch/arm/configs/tegra_defconfig:CONFIG_DEBUG_SLAB=y
> > arch/microblaze/configs/mmu_defconfig:CONFIG_DEBUG_SLAB=y
> >
> > $ git grep SLAB Documentation/
> >
> > [... some unrelated lines removed ...]
>
> Yep, I've wrote in the cover letter that to keep the series reasonable and
> limit Ccing other subsystems on some patches, not everything is cleaned up
> thoroughly
Ah, I see, Okay.
> and is left for further work (some already started coming in
> from others) that can be submitted to relevant subsystems.
I'll focus more on correctness rather than doing further work while reviewing.
> > Documentation/admin-guide/cgroup-v1/cpusets.rst:PFA_SPREAD_SLAB, and appropriately marked slab caches will allocate
> > Documentation/admin-guide/cgroup-v1/memory.rst: pages allocated by the SLAB or SLUB allocator are tracked. A copy
> > Documentation/admin-guide/kernel-per-CPU-kthreads.rst: CONFIG_SLAB=y, thus avoiding the slab allocator's periodic
> > Documentation/admin-guide/mm/pagemap.rst: The page is managed by the SLAB/SLUB kernel memory allocator.
> > Documentation/dev-tools/kasan.rst:For slab, both software KASAN modes support SLUB and SLAB allocators, while
> > Documentation/dev-tools/kfence.rst:of the sample interval, the next allocation through the main allocator (SLAB or
> > Documentation/mm/slub.rst:The basic philosophy of SLUB is very different from SLAB. SLAB
> > Documentation/mm/slub.rst: Sorry SLAB legacy issues)
> > Documentation/process/4.Coding.rst: - DEBUG_SLAB can find a variety of memory allocation and use errors; it
> > Documentation/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> > Documentation/scsi/ChangeLog.lpfc: CONFIG_DEBUG_SLAB set).
> > Documentation/translations/it_IT/process/4.Coding.rst: - DEBUG_SLAB può trovare svariati errori di uso e di allocazione di memoria;
> > Documentation/translations/it_IT/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> > Documentation/translations/ja_JP/SubmitChecklist:12: CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB,
> > Documentation/translations/zh_CN/dev-tools/kasan.rst:对于slab，两种软件KASAN模式都支持SLUB和SLAB分配器，而基于硬件标签的
> > Documentation/translations/zh_CN/process/4.Coding.rst: - DEBUG_SLAB 可以发现各种内存分配和使用错误；它应该用于大多数开发内核。
> > Documentation/translations/zh_CN/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> > Documentation/translations/zh_TW/dev-tools/kasan.rst:對於slab，兩種軟件KASAN模式都支持SLUB和SLAB分配器，而基於硬件標籤的
> > Documentation/translations/zh_TW/process/4.Coding.rst: - DEBUG_SLAB 可以發現各種內存分配和使用錯誤；它應該用於大多數開發內核。
> > Documentation/translations/zh_TW/process/submit-checklist.rst: ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
> >
> > --
> > Hyeonggon
>