From: "Mike Rapoport (IBM)" <[email protected]>
Hi,
Several architectures have ARCH_FORCE_MAX_ORDER in their Kconfig and
they all have wrong and misleading prompt and help text for this option.
Besides, some define insane limits for possible values of
ARCH_FORCE_MAX_ORDER, some carefully define ranges only for a subset of
possible configurations, some make this option configurable by users for no
good reason.
This set updates the prompt and help text everywhere and does its best to
update actual definitions of ranges where applicable.
kbuild generated a bunch of false positives because it assigns -1 to
ARCH_FORCE_MAX_ORDER, hopefully this will be fixed soon.
v2:
* arm64: show prompt for ARCH_FORCE_MAX_ORDER only if EXPERT (Catalin)
* Add Acked- and Reviewed-by tags (thanks Geert, Kirill and Max)
v1: https://lore.kernel.org/all/[email protected]
Mike Rapoport (IBM) (14):
arm: reword ARCH_FORCE_MAX_ORDER prompt and help text
arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER
arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
csky: drop ARCH_FORCE_MAX_ORDER
ia64: don't allow users to override ARCH_FORCE_MAX_ORDER
m68k: reword ARCH_FORCE_MAX_ORDER prompt and help text
nios2: reword ARCH_FORCE_MAX_ORDER prompt and help text
nios2: drop ranges for definition of ARCH_FORCE_MAX_ORDER
powerpc: reword ARCH_FORCE_MAX_ORDER prompt and help text
powerpc: drop ranges for definition of ARCH_FORCE_MAX_ORDER
sh: reword ARCH_FORCE_MAX_ORDER prompt and help text
sh: drop ranges for definition of ARCH_FORCE_MAX_ORDER
sparc: reword ARCH_FORCE_MAX_ORDER prompt and help text
xtensa: reword ARCH_FORCE_MAX_ORDER prompt and help text
arch/arm/Kconfig | 16 +++++++++-------
arch/arm64/Kconfig | 27 ++++++++++++---------------
arch/csky/Kconfig | 4 ----
arch/ia64/Kconfig | 3 +--
arch/m68k/Kconfig.cpu | 16 +++++++++-------
arch/nios2/Kconfig | 17 +++++++++--------
arch/powerpc/Kconfig | 22 +++++++++-------------
arch/sh/mm/Kconfig | 19 +++++++++----------
arch/sparc/Kconfig | 16 +++++++++-------
arch/xtensa/Kconfig | 16 +++++++++-------
10 files changed, 76 insertions(+), 80 deletions(-)
base-commit: 51551d71edbc998fd8c8afa7312db3d270f5998e
--
2.35.1
*** BLURB HERE ***
Mike Rapoport (IBM) (14):
arm: reword ARCH_FORCE_MAX_ORDER prompt and help text
arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER
arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
csky: drop ARCH_FORCE_MAX_ORDER
ia64: don't allow users to override ARCH_FORCE_MAX_ORDER
m68k: reword ARCH_FORCE_MAX_ORDER prompt and help text
nios2: reword ARCH_FORCE_MAX_ORDER prompt and help text
nios2: drop ranges for definition of ARCH_FORCE_MAX_ORDER
powerpc: reword ARCH_FORCE_MAX_ORDER prompt and help text
powerpc: drop ranges for definition of ARCH_FORCE_MAX_ORDER
sh: reword ARCH_FORCE_MAX_ORDER prompt and help text
sh: drop ranges for definition of ARCH_FORCE_MAX_ORDER
sparc: reword ARCH_FORCE_MAX_ORDER prompt and help text
xtensa: reword ARCH_FORCE_MAX_ORDER prompt and help text
arch/arm/Kconfig | 16 +++++++++-------
arch/arm64/Kconfig | 26 ++++++++++++--------------
arch/csky/Kconfig | 4 ----
arch/ia64/Kconfig | 3 +--
arch/m68k/Kconfig.cpu | 16 +++++++++-------
arch/nios2/Kconfig | 17 +++++++++--------
arch/powerpc/Kconfig | 22 +++++++++-------------
arch/sh/mm/Kconfig | 19 +++++++++----------
arch/sparc/Kconfig | 16 +++++++++-------
arch/xtensa/Kconfig | 16 +++++++++-------
10 files changed, 76 insertions(+), 79 deletions(-)
base-commit: 51551d71edbc998fd8c8afa7312db3d270f5998e
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/arm64/Kconfig | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7324032af859..cdaf52ac4018 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1487,24 +1487,24 @@ config XEN
# 16K | 27 | 14 | 13 | 11 |
# 64K | 29 | 16 | 13 | 13 |
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
+ int "Order of maximal physically contiguous allocations" if ARM64_4K_PAGES || ARM64_16K_PAGES
default "13" if ARM64_64K_PAGES
default "11" if ARM64_16K_PAGES
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
- We make sure that we can allocate up to a HugePage size for each configuration.
- Hence we have :
- MAX_ORDER = PMD_SHIFT - PAGE_SHIFT => PAGE_SHIFT - 3
+ The maximal size of allocation cannot exceed the size of the
+ section, so the value of MAX_ORDER should satisfy
- However for 4K, we choose a higher default value, 10 as opposed to 9, giving us
- 4M allocations matching the default size used by generic code.
+ MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
+
+ Don't change if unsure.
config UNMAP_KERNEL_AT_EL0
bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/arm/Kconfig | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 929e646e84b9..0b15384c62e6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1354,17 +1354,19 @@ config ARM_MODULE_PLTS
configurations. If unsure, say y.
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
+ int "Order of maximal physically contiguous allocations"
default "11" if SOC_AM33XX
default "8" if SA1111
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
+
+ Don't change if unsure.
config ALIGNMENT_TRAP
def_bool CPU_CP15_MMU
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The default value of ARCH_FORCE_MAX_ORDER matches the generic default
defined in the MM code, the architecture does not support huge pages, so
there is no need to keep ARCH_FORCE_MAX_ORDER option available.
Drop it.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/csky/Kconfig | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index c694fac43bed..00379a843c37 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -332,10 +332,6 @@ config HIGHMEM
select KMAP_LOCAL
default y
-config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
- default "10"
-
config DRAM_BASE
hex "DRAM start addr (the same with memory-section in dts)"
default 0x0
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
It is enough to keep default values for base and huge pages without
letting users to override ARCH_FORCE_MAX_ORDER.
Drop the prompt to make the option unvisible in *config.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/ia64/Kconfig | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 0d2f41fa56ee..b61437cae162 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -202,8 +202,7 @@ config IA64_CYCLONE
If you're unsure, answer N.
config ARCH_FORCE_MAX_ORDER
- int "MAX_ORDER (10 - 16)" if !HUGETLB_PAGE
- range 10 16 if !HUGETLB_PAGE
+ int
default "16" if HUGETLB_PAGE
default "10"
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
---
arch/m68k/Kconfig.cpu | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index c9df6572133f..e530bc8f240f 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -398,21 +398,23 @@ config SINGLE_MEMORY_CHUNK
Say N if not sure.
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order" if ADVANCED
+ int "Order of maximal physically contiguous allocations" if ADVANCED
depends on !SINGLE_MEMORY_CHUNK
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
For systems that have holes in their physical address space this
value also defines the minimal size of the hole that allows
freeing unused memory map.
+ Don't change if unsure.
+
config 060_WRITETHROUGH
bool "Use write-through caching for 68060 supervisor accesses"
depends on ADVANCED && M68060
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
nios2 defines range for ARCH_FORCE_MAX_ORDER allowing MAX_ORDER
up to 19, which implies maximal contiguous allocation size of 2^19
pages or 2GiB.
Drop bogus definition of ranges for ARCH_FORCE_MAX_ORDER and leave it a
simple integer with sensible default.
Users that *really* need to change the value of ARCH_FORCE_MAX_ORDER
will be able to do so but they won't be mislead by the bogus ranges.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/nios2/Kconfig | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index fcaa6bbda3fc..e5936417d3cd 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -46,7 +46,6 @@ source "kernel/Kconfig.hz"
config ARCH_FORCE_MAX_ORDER
int "Order of maximal physically contiguous allocations"
- range 8 19
default "10"
help
The kernel page allocator limits the size of maximal physically
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/powerpc/Kconfig | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 24d56536b269..c0095bf795ca 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -896,7 +896,7 @@ config DATA_SHIFT
8M pages will be pinned.
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
+ int "Order of maximal physically contiguous allocations"
range 7 8 if PPC64 && PPC_64K_PAGES
default "8" if PPC64 && PPC_64K_PAGES
range 12 12 if PPC64 && !PPC_64K_PAGES
@@ -910,17 +910,19 @@ config ARCH_FORCE_MAX_ORDER
range 10 63
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
The page size is not necessarily 4KB. For example, on 64-bit
systems, 64KB pages can be enabled via CONFIG_PPC_64K_PAGES. Keep
this in mind when choosing a value for this option.
+ Don't change if unsure.
+
config PPC_SUBPAGE_PROT
bool "Support setting protections for 4k subpages (subpage_prot syscall)"
default n
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/nios2/Kconfig | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 89708b95978c..fcaa6bbda3fc 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -45,16 +45,18 @@ menu "Kernel features"
source "kernel/Kconfig.hz"
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
+ int "Order of maximal physically contiguous allocations"
range 8 19
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
+
+ Don't change if unsure.
endmenu
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
PowerPC defines ranges for ARCH_FORCE_MAX_ORDER some of which are
insanely allowing MAX_ORDER up to 63, which implies maximal contiguous
allocation size of 2^63 pages.
Drop bogus definitions of ranges for ARCH_FORCE_MAX_ORDER and leave it a
simple integer with sensible defaults.
Users that *really* need to change the value of ARCH_FORCE_MAX_ORDER
will be able to do so but they won't be mislead by the bogus ranges.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/powerpc/Kconfig | 6 ------
1 file changed, 6 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c0095bf795ca..419be4a71004 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -897,17 +897,11 @@ config DATA_SHIFT
config ARCH_FORCE_MAX_ORDER
int "Order of maximal physically contiguous allocations"
- range 7 8 if PPC64 && PPC_64K_PAGES
default "8" if PPC64 && PPC_64K_PAGES
- range 12 12 if PPC64 && !PPC_64K_PAGES
default "12" if PPC64 && !PPC_64K_PAGES
- range 8 63 if PPC32 && PPC_16K_PAGES
default "8" if PPC32 && PPC_16K_PAGES
- range 6 63 if PPC32 && PPC_64K_PAGES
default "6" if PPC32 && PPC_64K_PAGES
- range 4 63 if PPC32 && PPC_256K_PAGES
default "4" if PPC32 && PPC_256K_PAGES
- range 10 63
default "10"
help
The kernel page allocator limits the size of maximal physically
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
It is not a good idea to change fundamental parameters of core memory
management. Having predefined ranges suggests that the values within
those ranges are sensible, but one has to *really* understand
implications of changing MAX_ORDER before actually amending it and
ranges don't help here.
Drop ranges in definition of ARCH_FORCE_MAX_ORDER and make its prompt
visible only if EXPERT=y
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
---
arch/arm64/Kconfig | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e60baf7859d1..7324032af859 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1487,11 +1487,9 @@ config XEN
# 16K | 27 | 14 | 13 | 11 |
# 64K | 29 | 16 | 13 | 13 |
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES
+ int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
default "13" if ARM64_64K_PAGES
- range 11 13 if ARM64_16K_PAGES
default "11" if ARM64_16K_PAGES
- range 10 15 if ARM64_4K_PAGES
default "10"
help
The kernel memory allocator divides physically contiguous memory
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
sh defines insane ranges for ARCH_FORCE_MAX_ORDER allowing MAX_ORDER
up to 63, which implies maximal contiguous allocation size of 2^63
pages.
Drop bogus definitions of ranges for ARCH_FORCE_MAX_ORDER and leave it a
simple integer with sensible defaults.
Users that *really* need to change the value of ARCH_FORCE_MAX_ORDER
will be able to do so but they won't be mislead by the bogus ranges.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/sh/mm/Kconfig | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index fb15ba1052ba..511c17aede4a 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -21,9 +21,7 @@ config PAGE_OFFSET
config ARCH_FORCE_MAX_ORDER
int "Order of maximal physically contiguous allocations"
default "8" if PAGE_SIZE_16KB
- range 6 63 if PAGE_SIZE_64KB
default "6" if PAGE_SIZE_64KB
- range 10 63
default "13" if !MMU
default "10"
help
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/sparc/Kconfig | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index e3242bf5a8df..959e43a1aaca 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -270,15 +270,17 @@ config ARCH_SPARSEMEM_DEFAULT
def_bool y if SPARC64
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
+ int "Order of maximal physically contiguous allocations"
default "12"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
+
+ Don't change if unsure.
if SPARC64 || COMPILE_TEST
source "kernel/power/Kconfig"
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/sh/mm/Kconfig | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index 40271090bd7d..fb15ba1052ba 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -19,8 +19,7 @@ config PAGE_OFFSET
default "0x00000000"
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
- range 8 63 if PAGE_SIZE_16KB
+ int "Order of maximal physically contiguous allocations"
default "8" if PAGE_SIZE_16KB
range 6 63 if PAGE_SIZE_64KB
default "6" if PAGE_SIZE_64KB
@@ -28,16 +27,18 @@ config ARCH_FORCE_MAX_ORDER
default "13" if !MMU
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
The page size is not necessarily 4KB. Keep this in mind when
choosing a value for this option.
+ Don't change if unsure.
+
config MEMORY_START
hex "Physical memory start address"
default "0x08000000"
--
2.35.1
From: "Mike Rapoport (IBM)" <[email protected]>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Reviewed-by: Max Filippov <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
---
arch/xtensa/Kconfig | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3eee334ba873..3c6e5471f025 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -772,15 +772,17 @@ config HIGHMEM
If unsure, say Y.
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order"
+ int "Order of maximal physically contiguous allocations"
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
+
+ Don't change if unsure.
endmenu
--
2.35.1
On 24 Mar 2023, at 1:22, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[email protected]>
>
> The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
> describe this configuration option.
>
> Update both to actually describe what this option does.
>
> Signed-off-by: Mike Rapoport (IBM) <[email protected]>
> Acked-by: Kirill A. Shutemov <[email protected]>
> ---
> arch/arm64/Kconfig | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7324032af859..cdaf52ac4018 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1487,24 +1487,24 @@ config XEN
> # 16K | 27 | 14 | 13 | 11 |
> # 64K | 29 | 16 | 13 | 13 |
> config ARCH_FORCE_MAX_ORDER
> - int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
> + int "Order of maximal physically contiguous allocations" if ARM64_4K_PAGES || ARM64_16K_PAGES
It seems that "if EXPERT" was dropped by accident here.
> default "13" if ARM64_64K_PAGES
> default "11" if ARM64_16K_PAGES
> default "10"
> help
> - The kernel memory allocator divides physically contiguous memory
> - blocks into "zones", where each zone is a power of two number of
> - pages. This option selects the largest power of two that the kernel
> - keeps in the memory allocator. If you need to allocate very large
> - blocks of physically contiguous memory, then you may need to
> - increase this value.
> + The kernel page allocator limits the size of maximal physically
> + contiguous allocations. The limit is called MAX_ORDER and it
> + defines the maximal power of two of number of pages that can be
> + allocated as a single contiguous block. This option allows
> + overriding the default setting when ability to allocate very
> + large blocks of physically contiguous memory is required.
>
> - We make sure that we can allocate up to a HugePage size for each configuration.
> - Hence we have :
> - MAX_ORDER = PMD_SHIFT - PAGE_SHIFT => PAGE_SHIFT - 3
> + The maximal size of allocation cannot exceed the size of the
> + section, so the value of MAX_ORDER should satisfy
>
> - However for 4K, we choose a higher default value, 10 as opposed to 9, giving us
> - 4M allocations matching the default size used by generic code.
> + MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
> +
> + Don't change if unsure.
>
> config UNMAP_KERNEL_AT_EL0
> bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
> --
> 2.35.1
--
Best Regards,
Yan, Zi
On 24 Mar 2023, at 1:22, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[email protected]>
>
> The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
> describe this configuration option.
>
> Update both to actually describe what this option does.
>
> Signed-off-by: Mike Rapoport (IBM) <[email protected]>
> Acked-by: Kirill A. Shutemov <[email protected]>
> ---
> arch/sh/mm/Kconfig | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
> index 40271090bd7d..fb15ba1052ba 100644
> --- a/arch/sh/mm/Kconfig
> +++ b/arch/sh/mm/Kconfig
> @@ -19,8 +19,7 @@ config PAGE_OFFSET
> default "0x00000000"
>
> config ARCH_FORCE_MAX_ORDER
> - int "Maximum zone order"
> - range 8 63 if PAGE_SIZE_16KB
This range is dropped in current patch, but the other ranges are dropped in
the next patch. But feel free to ignore this since ultimately the ranges
are all dropped.
> + int "Order of maximal physically contiguous allocations"
> default "8" if PAGE_SIZE_16KB
> range 6 63 if PAGE_SIZE_64KB
> default "6" if PAGE_SIZE_64KB
> @@ -28,16 +27,18 @@ config ARCH_FORCE_MAX_ORDER
> default "13" if !MMU
> default "10"
> help
> - The kernel memory allocator divides physically contiguous memory
> - blocks into "zones", where each zone is a power of two number of
> - pages. This option selects the largest power of two that the kernel
> - keeps in the memory allocator. If you need to allocate very large
> - blocks of physically contiguous memory, then you may need to
> - increase this value.
> + The kernel page allocator limits the size of maximal physically
> + contiguous allocations. The limit is called MAX_ORDER and it
> + defines the maximal power of two of number of pages that can be
> + allocated as a single contiguous block. This option allows
> + overriding the default setting when ability to allocate very
> + large blocks of physically contiguous memory is required.
>
> The page size is not necessarily 4KB. Keep this in mind when
> choosing a value for this option.
>
> + Don't change if unsure.
> +
> config MEMORY_START
> hex "Physical memory start address"
> default "0x08000000"
> --
> 2.35.1
--
Best Regards,
Yan, Zi
On 24 Mar 2023, at 1:22, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[email protected]>
>
> Hi,
>
> Several architectures have ARCH_FORCE_MAX_ORDER in their Kconfig and
> they all have wrong and misleading prompt and help text for this option.
>
> Besides, some define insane limits for possible values of
> ARCH_FORCE_MAX_ORDER, some carefully define ranges only for a subset of
> possible configurations, some make this option configurable by users for no
> good reason.
>
> This set updates the prompt and help text everywhere and does its best to
> update actual definitions of ranges where applicable.
>
> kbuild generated a bunch of false positives because it assigns -1 to
> ARCH_FORCE_MAX_ORDER, hopefully this will be fixed soon.
>
> v2:
> * arm64: show prompt for ARCH_FORCE_MAX_ORDER only if EXPERT (Catalin)
> * Add Acked- and Reviewed-by tags (thanks Geert, Kirill and Max)
>
> v1: https://lore.kernel.org/all/[email protected]
>
> Mike Rapoport (IBM) (14):
> arm: reword ARCH_FORCE_MAX_ORDER prompt and help text
> arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER
> arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
> csky: drop ARCH_FORCE_MAX_ORDER
> ia64: don't allow users to override ARCH_FORCE_MAX_ORDER
> m68k: reword ARCH_FORCE_MAX_ORDER prompt and help text
> nios2: reword ARCH_FORCE_MAX_ORDER prompt and help text
> nios2: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> powerpc: reword ARCH_FORCE_MAX_ORDER prompt and help text
> powerpc: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> sh: reword ARCH_FORCE_MAX_ORDER prompt and help text
> sh: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> sparc: reword ARCH_FORCE_MAX_ORDER prompt and help text
> xtensa: reword ARCH_FORCE_MAX_ORDER prompt and help text
>
> arch/arm/Kconfig | 16 +++++++++-------
> arch/arm64/Kconfig | 27 ++++++++++++---------------
> arch/csky/Kconfig | 4 ----
> arch/ia64/Kconfig | 3 +--
> arch/m68k/Kconfig.cpu | 16 +++++++++-------
> arch/nios2/Kconfig | 17 +++++++++--------
> arch/powerpc/Kconfig | 22 +++++++++-------------
> arch/sh/mm/Kconfig | 19 +++++++++----------
> arch/sparc/Kconfig | 16 +++++++++-------
> arch/xtensa/Kconfig | 16 +++++++++-------
> 10 files changed, 76 insertions(+), 80 deletions(-)
>
>
> base-commit: 51551d71edbc998fd8c8afa7312db3d270f5998e
LGTM, thanks. Reviewed-by: Zi Yan <[email protected]>
--
Best Regards,
Yan, Zi
On Fri, Mar 24, 2023 at 10:30:07AM -0400, Zi Yan wrote:
> On 24 Mar 2023, at 1:22, Mike Rapoport wrote:
>
> > From: "Mike Rapoport (IBM)" <[email protected]>
> >
> > Hi,
> >
> > Several architectures have ARCH_FORCE_MAX_ORDER in their Kconfig and
> > they all have wrong and misleading prompt and help text for this option.
> >
> > Besides, some define insane limits for possible values of
> > ARCH_FORCE_MAX_ORDER, some carefully define ranges only for a subset of
> > possible configurations, some make this option configurable by users for no
> > good reason.
> >
> > This set updates the prompt and help text everywhere and does its best to
> > update actual definitions of ranges where applicable.
> >
> > kbuild generated a bunch of false positives because it assigns -1 to
> > ARCH_FORCE_MAX_ORDER, hopefully this will be fixed soon.
> >
> > v2:
> > * arm64: show prompt for ARCH_FORCE_MAX_ORDER only if EXPERT (Catalin)
> > * Add Acked- and Reviewed-by tags (thanks Geert, Kirill and Max)
> >
> > v1: https://lore.kernel.org/all/[email protected]
> >
> > Mike Rapoport (IBM) (14):
> > arm: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER
> > arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > csky: drop ARCH_FORCE_MAX_ORDER
> > ia64: don't allow users to override ARCH_FORCE_MAX_ORDER
> > m68k: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > nios2: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > nios2: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> > powerpc: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > powerpc: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> > sh: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > sh: drop ranges for definition of ARCH_FORCE_MAX_ORDER
> > sparc: reword ARCH_FORCE_MAX_ORDER prompt and help text
> > xtensa: reword ARCH_FORCE_MAX_ORDER prompt and help text
> >
> > arch/arm/Kconfig | 16 +++++++++-------
> > arch/arm64/Kconfig | 27 ++++++++++++---------------
> > arch/csky/Kconfig | 4 ----
> > arch/ia64/Kconfig | 3 +--
> > arch/m68k/Kconfig.cpu | 16 +++++++++-------
> > arch/nios2/Kconfig | 17 +++++++++--------
> > arch/powerpc/Kconfig | 22 +++++++++-------------
> > arch/sh/mm/Kconfig | 19 +++++++++----------
> > arch/sparc/Kconfig | 16 +++++++++-------
> > arch/xtensa/Kconfig | 16 +++++++++-------
> > 10 files changed, 76 insertions(+), 80 deletions(-)
> >
> >
> > base-commit: 51551d71edbc998fd8c8afa7312db3d270f5998e
>
> LGTM, thanks. Reviewed-by: Zi Yan <[email protected]>
Thanks!
And thanks for spotting the mistakes in arm64 and sh patches.
> --
> Best Regards,
> Yan, Zi
--
Sincerely yours,
Mike.