| Message ID | 20240226161414.2316610-2-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arch: mm, vdso: consolidate PAGE_SIZE definition | expand |
On 2024-02-26 10:14 AM, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > These four architectures define the same Kconfig symbols for configuring > the page size. Move the logic into a common place where it can be shared > with all other architectures. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/Kconfig | 58 +++++++++++++++++++++++++++++-- > arch/hexagon/Kconfig | 25 +++---------- > arch/hexagon/include/asm/page.h | 6 +--- > arch/loongarch/Kconfig | 21 ++++------- > arch/loongarch/include/asm/page.h | 10 +----- > arch/mips/Kconfig | 58 +++---------------------------- > arch/mips/include/asm/page.h | 16 +-------- > arch/sh/include/asm/page.h | 13 +------ > arch/sh/mm/Kconfig | 42 +++++++--------------- > 9 files changed, 88 insertions(+), 161 deletions(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index a5af0edd3eb8..237cea01ed9b 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -1078,17 +1078,71 @@ config HAVE_ARCH_COMPAT_MMAP_BASES > and vice-versa 32-bit applications to call 64-bit mmap(). > Required for applications doing different bitness syscalls. > > +config HAVE_PAGE_SIZE_4KB > + bool > + > +config HAVE_PAGE_SIZE_8KB > + bool > + > +config HAVE_PAGE_SIZE_16KB > + bool > + > +config HAVE_PAGE_SIZE_32KB > + bool > + > +config HAVE_PAGE_SIZE_64KB > + bool > + > +config HAVE_PAGE_SIZE_256KB > + bool > + > +choice > + prompt "MMU page size" Should this have some generic help text (at least a warning about compatibility)? > + > +config PAGE_SIZE_4KB > + bool "4KB pages" > + depends on HAVE_PAGE_SIZE_4KB > + > +config PAGE_SIZE_8KB > + bool "8KB pages" > + depends on HAVE_PAGE_SIZE_8KB > + > +config PAGE_SIZE_16KB > + bool "16KB pages" > + depends on HAVE_PAGE_SIZE_16KB > + > +config PAGE_SIZE_32KB > + bool "32KB pages" > + depends on HAVE_PAGE_SIZE_32KB > + > +config PAGE_SIZE_64KB > + bool "64KB pages" > + depends on HAVE_PAGE_SIZE_64KB > + > +config PAGE_SIZE_256KB > + bool "256KB pages" > + depends on HAVE_PAGE_SIZE_256KB > + > +endchoice > + > config PAGE_SIZE_LESS_THAN_64KB > def_bool y > - depends on !ARM64_64K_PAGES > depends on !PAGE_SIZE_64KB > - depends on !PARISC_PAGE_SIZE_64KB > depends on PAGE_SIZE_LESS_THAN_256KB > > config PAGE_SIZE_LESS_THAN_256KB > def_bool y > depends on !PAGE_SIZE_256KB > > +config PAGE_SHIFT > + int > + default 12 if PAGE_SIZE_4KB > + default 13 if PAGE_SIZE_8KB > + default 14 if PAGE_SIZE_16KB > + default 15 if PAGE_SIZE_32KB > + default 16 if PAGE_SIZE_64KB > + default 18 if PAGE_SIZE_256KB > + > # This allows to use a set of generic functions to determine mmap base > # address by giving priority to top-down scheme only if the process > # is not in legacy mode (compat task, unlimited stack size or > diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig > index a880ee067d2e..aac46ee1a000 100644 > --- a/arch/hexagon/Kconfig > +++ b/arch/hexagon/Kconfig > @@ -8,6 +8,11 @@ config HEXAGON > select ARCH_HAS_SYNC_DMA_FOR_DEVICE > select ARCH_NO_PREEMPT > select DMA_GLOBAL_POOL > + select FRAME_POINTER Looks like a paste error. > + select HAVE_PAGE_SIZE_4KB > + select HAVE_PAGE_SIZE_16KB > + select HAVE_PAGE_SIZE_64KB > + select HAVE_PAGE_SIZE_256KB > # Other pending projects/to-do items. > # select HAVE_REGS_AND_STACK_ACCESS_API > # select HAVE_HW_BREAKPOINT if PERF_EVENTS > @@ -120,26 +125,6 @@ config NR_CPUS > This is purely to save memory - each supported CPU adds > approximately eight kilobytes to the kernel image. > > -choice > - prompt "Kernel page size" > - default PAGE_SIZE_4KB > - help > - Changes the default page size; use with caution. > - > -config PAGE_SIZE_4KB > - bool "4KB" > - > -config PAGE_SIZE_16KB > - bool "16KB" > - > -config PAGE_SIZE_64KB > - bool "64KB" > - > -config PAGE_SIZE_256KB > - bool "256KB" > - > -endchoice > - > source "kernel/Kconfig.hz" > > endmenu > diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h > index 10f1bc07423c..65c9bac639fa 100644 > --- a/arch/hexagon/include/asm/page.h > +++ b/arch/hexagon/include/asm/page.h > @@ -13,27 +13,22 @@ > /* This is probably not the most graceful way to handle this. */ > > #ifdef CONFIG_PAGE_SIZE_4KB > -#define PAGE_SHIFT 12 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_4KB > #endif > > #ifdef CONFIG_PAGE_SIZE_16KB > -#define PAGE_SHIFT 14 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_16KB > #endif > > #ifdef CONFIG_PAGE_SIZE_64KB > -#define PAGE_SHIFT 16 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_64KB > #endif > > #ifdef CONFIG_PAGE_SIZE_256KB > -#define PAGE_SHIFT 18 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_256KB > #endif > > #ifdef CONFIG_PAGE_SIZE_1MB > -#define PAGE_SHIFT 20 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_1MB > #endif The corresponding Kconfig option does not exist (and did not exist before this patch). > > @@ -50,6 +45,7 @@ > #define HVM_HUGEPAGE_SIZE 0x5 > #endif > > +#define PAGE_SHIFT CONFIG_PAGE_SHIFT > #define PAGE_SIZE (1UL << PAGE_SHIFT) > #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) >
Le 26/02/2024 à 17:14, Arnd Bergmann a écrit : > From: Arnd Bergmann <arnd@arndb.de> > > These four architectures define the same Kconfig symbols for configuring > the page size. Move the logic into a common place where it can be shared > with all other architectures. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/Kconfig | 58 +++++++++++++++++++++++++++++-- > arch/hexagon/Kconfig | 25 +++---------- > arch/hexagon/include/asm/page.h | 6 +--- > arch/loongarch/Kconfig | 21 ++++------- > arch/loongarch/include/asm/page.h | 10 +----- > arch/mips/Kconfig | 58 +++---------------------------- > arch/mips/include/asm/page.h | 16 +-------- > arch/sh/include/asm/page.h | 13 +------ > arch/sh/mm/Kconfig | 42 +++++++--------------- > 9 files changed, 88 insertions(+), 161 deletions(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index a5af0edd3eb8..237cea01ed9b 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -1078,17 +1078,71 @@ config HAVE_ARCH_COMPAT_MMAP_BASES > and vice-versa 32-bit applications to call 64-bit mmap(). > Required for applications doing different bitness syscalls. > > +config HAVE_PAGE_SIZE_4KB > + bool > + > +config HAVE_PAGE_SIZE_8KB > + bool > + > +config HAVE_PAGE_SIZE_16KB > + bool > + > +config HAVE_PAGE_SIZE_32KB > + bool > + > +config HAVE_PAGE_SIZE_64KB > + bool > + > +config HAVE_PAGE_SIZE_256KB > + bool > + > +choice > + prompt "MMU page size" > + That's a nice re-factor. The only drawback I see is that we are loosing several interesting arch-specific comments/help text. Don't know if there could be an easy way to keep them. > +config PAGE_SIZE_4KB > + bool "4KB pages" > + depends on HAVE_PAGE_SIZE_4KB > + > +config PAGE_SIZE_8KB > + bool "8KB pages" > + depends on HAVE_PAGE_SIZE_8KB > + > +config PAGE_SIZE_16KB > + bool "16KB pages" > + depends on HAVE_PAGE_SIZE_16KB > + > +config PAGE_SIZE_32KB > + bool "32KB pages" > + depends on HAVE_PAGE_SIZE_32KB > + > +config PAGE_SIZE_64KB > + bool "64KB pages" > + depends on HAVE_PAGE_SIZE_64KB > + > +config PAGE_SIZE_256KB > + bool "256KB pages" > + depends on HAVE_PAGE_SIZE_256KB Hexagon seem to also use CONFIG_PAGE_SIZE_1MB ? > + > +endchoice > + > config PAGE_SIZE_LESS_THAN_64KB > def_bool y > - depends on !ARM64_64K_PAGES > depends on !PAGE_SIZE_64KB > - depends on !PARISC_PAGE_SIZE_64KB > depends on PAGE_SIZE_LESS_THAN_256KB > > config PAGE_SIZE_LESS_THAN_256KB > def_bool y > depends on !PAGE_SIZE_256KB > > +config PAGE_SHIFT > + int > + default 12 if PAGE_SIZE_4KB > + default 13 if PAGE_SIZE_8KB > + default 14 if PAGE_SIZE_16KB > + default 15 if PAGE_SIZE_32KB > + default 16 if PAGE_SIZE_64KB > + default 18 if PAGE_SIZE_256KB > + > # This allows to use a set of generic functions to determine mmap base > # address by giving priority to top-down scheme only if the process > # is not in legacy mode (compat task, unlimited stack size or > diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig > index a880ee067d2e..aac46ee1a000 100644 > --- a/arch/hexagon/Kconfig > +++ b/arch/hexagon/Kconfig > @@ -8,6 +8,11 @@ config HEXAGON > select ARCH_HAS_SYNC_DMA_FOR_DEVICE > select ARCH_NO_PREEMPT > select DMA_GLOBAL_POOL > + select FRAME_POINTER > + select HAVE_PAGE_SIZE_4KB > + select HAVE_PAGE_SIZE_16KB > + select HAVE_PAGE_SIZE_64KB > + select HAVE_PAGE_SIZE_256KB > # Other pending projects/to-do items. > # select HAVE_REGS_AND_STACK_ACCESS_API > # select HAVE_HW_BREAKPOINT if PERF_EVENTS > @@ -120,26 +125,6 @@ config NR_CPUS > This is purely to save memory - each supported CPU adds > approximately eight kilobytes to the kernel image. > > -choice > - prompt "Kernel page size" > - default PAGE_SIZE_4KB > - help > - Changes the default page size; use with caution. > - > -config PAGE_SIZE_4KB > - bool "4KB" > - > -config PAGE_SIZE_16KB > - bool "16KB" > - > -config PAGE_SIZE_64KB > - bool "64KB" > - > -config PAGE_SIZE_256KB > - bool "256KB" > - > -endchoice > - > source "kernel/Kconfig.hz" > > endmenu > diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h > index 10f1bc07423c..65c9bac639fa 100644 > --- a/arch/hexagon/include/asm/page.h > +++ b/arch/hexagon/include/asm/page.h > @@ -13,27 +13,22 @@ > /* This is probably not the most graceful way to handle this. */ > > #ifdef CONFIG_PAGE_SIZE_4KB > -#define PAGE_SHIFT 12 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_4KB > #endif > > #ifdef CONFIG_PAGE_SIZE_16KB > -#define PAGE_SHIFT 14 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_16KB > #endif > > #ifdef CONFIG_PAGE_SIZE_64KB > -#define PAGE_SHIFT 16 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_64KB > #endif > > #ifdef CONFIG_PAGE_SIZE_256KB > -#define PAGE_SHIFT 18 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_256KB > #endif > > #ifdef CONFIG_PAGE_SIZE_1MB > -#define PAGE_SHIFT 20 > #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_1MB > #endif > > @@ -50,6 +45,7 @@ > #define HVM_HUGEPAGE_SIZE 0x5 > #endif > > +#define PAGE_SHIFT CONFIG_PAGE_SHIFT > #define PAGE_SIZE (1UL << PAGE_SHIFT) > #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) > Could we move PAGE_SIZE and PAGE_MASK in a generic/core header instead of having it duplicated for each arch ? Christophe
Hi Arnd, On Mon, Feb 26, 2024 at 5:14 PM Arnd Bergmann <arnd@kernel.org> wrote: > From: Arnd Bergmann <arnd@arndb.de> > > These four architectures define the same Kconfig symbols for configuring > the page size. Move the logic into a common place where it can be shared > with all other architectures. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Thanks for your patch! > --- a/arch/Kconfig > +++ b/arch/Kconfig > +config PAGE_SIZE_4KB > + bool "4KB pages" Now you got rid of the 4000-byte ("4kB") pages and friends, please do not replace these by Kelvin-bytes, and use the official binary prefixes => "4 KiB". > + depends on HAVE_PAGE_SIZE_4KB Gr{oetje,eeting}s, Geert
On Mon, Feb 26, 2024, at 17:55, Samuel Holland wrote: > On 2024-02-26 10:14 AM, Arnd Bergmann wrote: >> >> +config HAVE_PAGE_SIZE_4KB >> + bool >> + >> +config HAVE_PAGE_SIZE_8KB >> + bool >> + >> +config HAVE_PAGE_SIZE_16KB >> + bool >> + >> +config HAVE_PAGE_SIZE_32KB >> + bool >> + >> +config HAVE_PAGE_SIZE_64KB >> + bool >> + >> +config HAVE_PAGE_SIZE_256KB >> + bool >> + >> +choice >> + prompt "MMU page size" > > Should this have some generic help text (at least a warning about > compatibility)? Good point. I've added some of this now, based on the mips text with some generalizations for other architectures: config PAGE_SIZE_4KB bool "4KiB pages" depends on HAVE_PAGE_SIZE_4KB help This option select the standard 4KiB Linux page size and the only available option on many architectures. Using 4KiB page size will minimize memory consumption and is therefore recommended for low memory systems. Some software that is written for x86 systems makes incorrect assumptions about the page size and only runs on 4KiB pages. config PAGE_SIZE_8KB bool "8KiB pages" depends on HAVE_PAGE_SIZE_8KB help This option is the only supported page size on a few older processors, and can be slightly faster than 4KiB pages. config PAGE_SIZE_16KB bool "16KiB pages" depends on HAVE_PAGE_SIZE_16KB help This option is usually a good compromise between memory consumption and performance for typical desktop and server workloads, often saving a level of page table lookups compared to 4KB pages as well as reducing TLB pressure and overhead of per-page operations in the kernel at the expense of a larger page cache. config PAGE_SIZE_32KB bool "32KiB pages" depends on HAVE_PAGE_SIZE_32KB Using 32KiB page size will result in slightly higher performance kernel at the price of higher memory consumption compared to 16KiB pages. This option is available only on cnMIPS cores. Note that you will need a suitable Linux distribution to support this. config PAGE_SIZE_64KB bool "64KiB pages" depends on HAVE_PAGE_SIZE_64KB Using 64KiB page size will result in slightly higher performance kernel at the price of much higher memory consumption compared to 4KiB or 16KiB pages. This is not suitable for general-purpose workloads but the better performance may be worth the cost for certain types of supercomputing or database applications that work mostly with large in-memory data rather than small files. config PAGE_SIZE_256KB bool "256KiB pages" depends on HAVE_PAGE_SIZE_256KB help 256KB pages have little practical value due to their extreme memory usage. >> diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig >> index a880ee067d2e..aac46ee1a000 100644 >> --- a/arch/hexagon/Kconfig >> +++ b/arch/hexagon/Kconfig >> @@ -8,6 +8,11 @@ config HEXAGON >> select ARCH_HAS_SYNC_DMA_FOR_DEVICE >> select ARCH_NO_PREEMPT >> select DMA_GLOBAL_POOL >> + select FRAME_POINTER > > Looks like a paste error. > Fixed, thanks! I think that happened during a rebase. >> #ifdef CONFIG_PAGE_SIZE_1MB >> -#define PAGE_SHIFT 20 >> #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_1MB >> #endif > > The corresponding Kconfig option does not exist (and did not exist before this > patch). Yes, I noticed that as well. It's clearly harmless. Arnd
On Mon, Feb 26, 2024, at 20:02, Christophe Leroy wrote: > Le 26/02/2024 à 17:14, Arnd Bergmann a écrit : >> From: Arnd Bergmann <arnd@arndb.de> > > That's a nice re-factor. > > The only drawback I see is that we are loosing several interesting > arch-specific comments/help text. Don't know if there could be an easy > way to keep them. This is what I have now, trying to write it as generic as possible while still giving useful advice: config PAGE_SIZE_4KB bool "4KiB pages" depends on HAVE_PAGE_SIZE_4KB help This option select the standard 4KiB Linux page size and the only available option on many architectures. Using 4KiB page size will minimize memory consumption and is therefore recommended for low memory systems. Some software that is written for x86 systems makes incorrect assumptions about the page size and only runs on 4KiB pages. config PAGE_SIZE_8KB bool "8KiB pages" depends on HAVE_PAGE_SIZE_8KB help This option is the only supported page size on a few older processors, and can be slightly faster than 4KiB pages. config PAGE_SIZE_16KB bool "16KiB pages" depends on HAVE_PAGE_SIZE_16KB help This option is usually a good compromise between memory consumption and performance for typical desktop and server workloads, often saving a level of page table lookups compared to 4KB pages as well as reducing TLB pressure and overhead of per-page operations in the kernel at the expense of a larger page cache. config PAGE_SIZE_32KB bool "32KiB pages" depends on HAVE_PAGE_SIZE_32KB Using 32KiB page size will result in slightly higher performance kernel at the price of higher memory consumption compared to 16KiB pages. This option is available only on cnMIPS cores. Note that you will need a suitable Linux distribution to support this. config PAGE_SIZE_64KB bool "64KiB pages" depends on HAVE_PAGE_SIZE_64KB Using 64KiB page size will result in slightly higher performance kernel at the price of much higher memory consumption compared to 4KiB or 16KiB pages. This is not suitable for general-purpose workloads but the better performance may be worth the cost for certain types of supercomputing or database applications that work mostly with large in-memory data rather than small files. config PAGE_SIZE_256KB bool "256KiB pages" depends on HAVE_PAGE_SIZE_256KB help 256KB pages have little practical value due to their extreme memory usage. Let me know if you think some of this should be adapted further. >> >> +#define PAGE_SHIFT CONFIG_PAGE_SHIFT >> #define PAGE_SIZE (1UL << PAGE_SHIFT) >> #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) >> > > Could we move PAGE_SIZE and PAGE_MASK in a generic/core header instead > of having it duplicated for each arch ? Yes, but I'm leaving this for a follow-up series, since I had to stop somewhere and there is always room for cleanup up headers further ;-) Arnd
On Tue, Feb 27, 2024, at 09:45, Geert Uytterhoeven wrote: > >> +config PAGE_SIZE_4KB >> + bool "4KB pages" > > Now you got rid of the 4000-byte ("4kB") pages and friends, please > do not replace these by Kelvin-bytes, and use the official binary > prefixes => "4 KiB". > Done, thanks. Arnd
Le 27/02/2024 à 16:40, Arnd Bergmann a écrit : > On Mon, Feb 26, 2024, at 17:55, Samuel Holland wrote: >> On 2024-02-26 10:14 AM, Arnd Bergmann wrote: >>> >>> +config HAVE_PAGE_SIZE_4KB >>> + bool >>> + >>> +config HAVE_PAGE_SIZE_8KB >>> + bool >>> + >>> +config HAVE_PAGE_SIZE_16KB >>> + bool >>> + >>> +config HAVE_PAGE_SIZE_32KB >>> + bool >>> + >>> +config HAVE_PAGE_SIZE_64KB >>> + bool >>> + >>> +config HAVE_PAGE_SIZE_256KB >>> + bool >>> + >>> +choice >>> + prompt "MMU page size" >> >> Should this have some generic help text (at least a warning about >> compatibility)? > > Good point. I've added some of this now, based on the mips > text with some generalizations for other architectures: > > config PAGE_SIZE_4KB > bool "4KiB pages" > depends on HAVE_PAGE_SIZE_4KB > help > This option select the standard 4KiB Linux page size and the only > available option on many architectures. Using 4KiB page size will > minimize memory consumption and is therefore recommended for low > memory systems. > Some software that is written for x86 systems makes incorrect > assumptions about the page size and only runs on 4KiB pages. > > config PAGE_SIZE_8KB > bool "8KiB pages" > depends on HAVE_PAGE_SIZE_8KB > help > This option is the only supported page size on a few older > processors, and can be slightly faster than 4KiB pages. > > config PAGE_SIZE_16KB > bool "16KiB pages" > depends on HAVE_PAGE_SIZE_16KB > help > This option is usually a good compromise between memory > consumption and performance for typical desktop and server > workloads, often saving a level of page table lookups compared > to 4KB pages as well as reducing TLB pressure and overhead of > per-page operations in the kernel at the expense of a larger > page cache. > > config PAGE_SIZE_32KB > bool "32KiB pages" > depends on HAVE_PAGE_SIZE_32KB > Using 32KiB page size will result in slightly higher performance > kernel at the price of higher memory consumption compared to > 16KiB pages. This option is available only on cnMIPS cores. > Note that you will need a suitable Linux distribution to > support this. > > config PAGE_SIZE_64KB > bool "64KiB pages" > depends on HAVE_PAGE_SIZE_64KB > Using 64KiB page size will result in slightly higher performance > kernel at the price of much higher memory consumption compared to > 4KiB or 16KiB pages. > This is not suitable for general-purpose workloads but the > better performance may be worth the cost for certain types of > supercomputing or database applications that work mostly with > large in-memory data rather than small files. > > config PAGE_SIZE_256KB > bool "256KiB pages" > depends on HAVE_PAGE_SIZE_256KB > help > 256KB pages have little practical value due to their extreme > memory usage. For 256K pages, powerpc has the following help. I think you should have it too: The kernel will only be able to run applications that have been compiled with '-zmax-page-size' set to 256K (the default is 64K) using binutils later than 2.17.50.0.3, or by patching the ELF_MAXPAGESIZE definition from 0x10000 to 0x40000 in older versions.
On Tue, Feb 27, 2024, at 16:44, Christophe Leroy wrote: > Le 27/02/2024 à 16:40, Arnd Bergmann a écrit : >> On Mon, Feb 26, 2024, at 17:55, Samuel Holland wrote: > > > For 256K pages, powerpc has the following help. I think you should have > it too: > > The kernel will only be able to run applications that have been > compiled with '-zmax-page-size' set to 256K (the default is 64K) using > binutils later than 2.17.50.0.3, or by patching the ELF_MAXPAGESIZE > definition from 0x10000 to 0x40000 in older versions. I don't think we need to mention pre-2.18 binutils any more, but the rest seems useful, changed the text now to config PAGE_SIZE_256KB bool "256KiB pages" depends on HAVE_PAGE_SIZE_256KB help 256KiB pages have little practical value due to their extreme memory usage. The kernel will only be able to run applications that have been compiled with '-zmax-page-size' set to 256KiB (the default is 64KiB or 4KiB on most architectures). Arnd
diff --git a/arch/Kconfig b/arch/Kconfig index a5af0edd3eb8..237cea01ed9b 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1078,17 +1078,71 @@ config HAVE_ARCH_COMPAT_MMAP_BASES and vice-versa 32-bit applications to call 64-bit mmap(). Required for applications doing different bitness syscalls. +config HAVE_PAGE_SIZE_4KB + bool + +config HAVE_PAGE_SIZE_8KB + bool + +config HAVE_PAGE_SIZE_16KB + bool + +config HAVE_PAGE_SIZE_32KB + bool + +config HAVE_PAGE_SIZE_64KB + bool + +config HAVE_PAGE_SIZE_256KB + bool + +choice + prompt "MMU page size" + +config PAGE_SIZE_4KB + bool "4KB pages" + depends on HAVE_PAGE_SIZE_4KB + +config PAGE_SIZE_8KB + bool "8KB pages" + depends on HAVE_PAGE_SIZE_8KB + +config PAGE_SIZE_16KB + bool "16KB pages" + depends on HAVE_PAGE_SIZE_16KB + +config PAGE_SIZE_32KB + bool "32KB pages" + depends on HAVE_PAGE_SIZE_32KB + +config PAGE_SIZE_64KB + bool "64KB pages" + depends on HAVE_PAGE_SIZE_64KB + +config PAGE_SIZE_256KB + bool "256KB pages" + depends on HAVE_PAGE_SIZE_256KB + +endchoice + config PAGE_SIZE_LESS_THAN_64KB def_bool y - depends on !ARM64_64K_PAGES depends on !PAGE_SIZE_64KB - depends on !PARISC_PAGE_SIZE_64KB depends on PAGE_SIZE_LESS_THAN_256KB config PAGE_SIZE_LESS_THAN_256KB def_bool y depends on !PAGE_SIZE_256KB +config PAGE_SHIFT + int + default 12 if PAGE_SIZE_4KB + default 13 if PAGE_SIZE_8KB + default 14 if PAGE_SIZE_16KB + default 15 if PAGE_SIZE_32KB + default 16 if PAGE_SIZE_64KB + default 18 if PAGE_SIZE_256KB + # This allows to use a set of generic functions to determine mmap base # address by giving priority to top-down scheme only if the process # is not in legacy mode (compat task, unlimited stack size or diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index a880ee067d2e..aac46ee1a000 100644 --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -8,6 +8,11 @@ config HEXAGON select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_NO_PREEMPT select DMA_GLOBAL_POOL + select FRAME_POINTER + select HAVE_PAGE_SIZE_4KB + select HAVE_PAGE_SIZE_16KB + select HAVE_PAGE_SIZE_64KB + select HAVE_PAGE_SIZE_256KB # Other pending projects/to-do items. # select HAVE_REGS_AND_STACK_ACCESS_API # select HAVE_HW_BREAKPOINT if PERF_EVENTS @@ -120,26 +125,6 @@ config NR_CPUS This is purely to save memory - each supported CPU adds approximately eight kilobytes to the kernel image. -choice - prompt "Kernel page size" - default PAGE_SIZE_4KB - help - Changes the default page size; use with caution. - -config PAGE_SIZE_4KB - bool "4KB" - -config PAGE_SIZE_16KB - bool "16KB" - -config PAGE_SIZE_64KB - bool "64KB" - -config PAGE_SIZE_256KB - bool "256KB" - -endchoice - source "kernel/Kconfig.hz" endmenu diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h index 10f1bc07423c..65c9bac639fa 100644 --- a/arch/hexagon/include/asm/page.h +++ b/arch/hexagon/include/asm/page.h @@ -13,27 +13,22 @@ /* This is probably not the most graceful way to handle this. */ #ifdef CONFIG_PAGE_SIZE_4KB -#define PAGE_SHIFT 12 #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_4KB #endif #ifdef CONFIG_PAGE_SIZE_16KB -#define PAGE_SHIFT 14 #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_16KB #endif #ifdef CONFIG_PAGE_SIZE_64KB -#define PAGE_SHIFT 16 #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_64KB #endif #ifdef CONFIG_PAGE_SIZE_256KB -#define PAGE_SHIFT 18 #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_256KB #endif #ifdef CONFIG_PAGE_SIZE_1MB -#define PAGE_SHIFT 20 #define HEXAGON_L1_PTE_SIZE __HVM_PDE_S_1MB #endif @@ -50,6 +45,7 @@ #define HVM_HUGEPAGE_SIZE 0x5 #endif +#define PAGE_SHIFT CONFIG_PAGE_SHIFT #define PAGE_SIZE (1UL << PAGE_SHIFT) #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 929f68926b34..b274784c2e26 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -227,15 +227,6 @@ config MACH_LOONGSON64 config FIX_EARLYCON_MEM def_bool y -config PAGE_SIZE_4KB - bool - -config PAGE_SIZE_16KB - bool - -config PAGE_SIZE_64KB - bool - config PGTABLE_2LEVEL bool @@ -288,7 +279,7 @@ choice config 4KB_3LEVEL bool "4KB with 3 levels" - select PAGE_SIZE_4KB + select HAVE_PAGE_SIZE_4KB select PGTABLE_3LEVEL help This option selects 4KB page size with 3 level page tables, which @@ -296,7 +287,7 @@ config 4KB_3LEVEL config 4KB_4LEVEL bool "4KB with 4 levels" - select PAGE_SIZE_4KB + select HAVE_PAGE_SIZE_4KB select PGTABLE_4LEVEL help This option selects 4KB page size with 4 level page tables, which @@ -304,7 +295,7 @@ config 4KB_4LEVEL config 16KB_2LEVEL bool "16KB with 2 levels" - select PAGE_SIZE_16KB + select HAVE_PAGE_SIZE_16KB select PGTABLE_2LEVEL help This option selects 16KB page size with 2 level page tables, which @@ -312,7 +303,7 @@ config 16KB_2LEVEL config 16KB_3LEVEL bool "16KB with 3 levels" - select PAGE_SIZE_16KB + select HAVE_PAGE_SIZE_16KB select PGTABLE_3LEVEL help This option selects 16KB page size with 3 level page tables, which @@ -320,7 +311,7 @@ config 16KB_3LEVEL config 64KB_2LEVEL bool "64KB with 2 levels" - select PAGE_SIZE_64KB + select HAVE_PAGE_SIZE_64KB select PGTABLE_2LEVEL help This option selects 64KB page size with 2 level page tables, which @@ -328,7 +319,7 @@ config 64KB_2LEVEL config 64KB_3LEVEL bool "64KB with 3 levels" - select PAGE_SIZE_64KB + select HAVE_PAGE_SIZE_64KB select PGTABLE_3LEVEL help This option selects 64KB page size with 3 level page tables, which diff --git a/arch/loongarch/include/asm/page.h b/arch/loongarch/include/asm/page.h index 63f137ce82a4..afb6fa16b826 100644 --- a/arch/loongarch/include/asm/page.h +++ b/arch/loongarch/include/asm/page.h @@ -11,15 +11,7 @@ /* * PAGE_SHIFT determines the page size */ -#ifdef CONFIG_PAGE_SIZE_4KB -#define PAGE_SHIFT 12 -#endif -#ifdef CONFIG_PAGE_SIZE_16KB -#define PAGE_SHIFT 14 -#endif -#ifdef CONFIG_PAGE_SIZE_64KB -#define PAGE_SHIFT 16 -#endif +#define PAGE_SHIFT CONFIG_PAGE_SHIFT #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE - 1)) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 797ae590ebdb..24bac93affee 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -81,6 +81,9 @@ config MIPS select HAVE_LD_DEAD_CODE_DATA_ELIMINATION select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI + select HAVE_PAGE_SIZE_4KB if !CPU_LOONGSON2EF && !CPU_LOONGSON64 + select HAVE_PAGE_SIZE_16KB if !CPU_R3000 + select HAVE_PAGE_SIZE_64KB if !CPU_R3000 select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP @@ -1608,6 +1611,8 @@ config CPU_CAVIUM_OCTEON depends on SYS_HAS_CPU_CAVIUM_OCTEON select CPU_HAS_PREFETCH select CPU_SUPPORTS_64BIT_KERNEL + select HAVE_PAGE_SIZE_8KB if !MIPS_VA_BITS_48 + select HAVE_PAGE_SIZE_32KB if !MIPS_VA_BITS_48 select WEAK_ORDERING select CPU_SUPPORTS_HIGHMEM select CPU_SUPPORTS_HUGEPAGES @@ -2029,59 +2034,6 @@ config ZBOOT_LOAD_ADDRESS This is only used if non-zero. -choice - prompt "Kernel page size" - default PAGE_SIZE_4KB - -config PAGE_SIZE_4KB - bool "4kB" - depends on !CPU_LOONGSON2EF && !CPU_LOONGSON64 - help - This option select the standard 4kB Linux page size. On some - R3000-family processors this is the only available page size. Using - 4kB page size will minimize memory consumption and is therefore - recommended for low memory systems. - -config PAGE_SIZE_8KB - bool "8kB" - depends on CPU_CAVIUM_OCTEON - depends on !MIPS_VA_BITS_48 - help - Using 8kB page size will result in higher performance kernel at - the price of higher memory consumption. This option is available - only on cnMIPS processors. Note that you will need a suitable Linux - distribution to support this. - -config PAGE_SIZE_16KB - bool "16kB" - depends on !CPU_R3000 - help - Using 16kB page size will result in higher performance kernel at - the price of higher memory consumption. This option is available on - all non-R3000 family processors. Note that you will need a suitable - Linux distribution to support this. - -config PAGE_SIZE_32KB - bool "32kB" - depends on CPU_CAVIUM_OCTEON - depends on !MIPS_VA_BITS_48 - help - Using 32kB page size will result in higher performance kernel at - the price of higher memory consumption. This option is available - only on cnMIPS cores. Note that you will need a suitable Linux - distribution to support this. - -config PAGE_SIZE_64KB - bool "64kB" - depends on !CPU_R3000 - help - Using 64kB page size will result in higher performance kernel at - the price of higher memory consumption. This option is available on - all non-R3000 family processor. Not that at the time of this - writing this option is still high experimental. - -endchoice - config ARCH_FORCE_MAX_ORDER int "Maximum zone order" default "13" if MIPS_HUGE_TLB_SUPPORT && PAGE_SIZE_64KB diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index ef9585d96f6b..4609cb0326cf 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -17,21 +17,7 @@ /* * PAGE_SHIFT determines the page size */ -#ifdef CONFIG_PAGE_SIZE_4KB -#define PAGE_SHIFT 12 -#endif -#ifdef CONFIG_PAGE_SIZE_8KB -#define PAGE_SHIFT 13 -#endif -#ifdef CONFIG_PAGE_SIZE_16KB -#define PAGE_SHIFT 14 -#endif -#ifdef CONFIG_PAGE_SIZE_32KB -#define PAGE_SHIFT 15 -#endif -#ifdef CONFIG_PAGE_SIZE_64KB -#define PAGE_SHIFT 16 -#endif +#define PAGE_SHIFT CONFIG_PAGE_SHIFT #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h index 62f4b9edcb98..f780b467e75d 100644 --- a/arch/sh/include/asm/page.h +++ b/arch/sh/include/asm/page.h @@ -9,18 +9,7 @@ #include <linux/const.h> /* PAGE_SHIFT determines the page size */ -#if defined(CONFIG_PAGE_SIZE_4KB) -# define PAGE_SHIFT 12 -#elif defined(CONFIG_PAGE_SIZE_8KB) -# define PAGE_SHIFT 13 -#elif defined(CONFIG_PAGE_SIZE_16KB) -# define PAGE_SHIFT 14 -#elif defined(CONFIG_PAGE_SIZE_64KB) -# define PAGE_SHIFT 16 -#else -# error "Bogus kernel page size?" -#endif - +#define PAGE_SHIFT CONFIG_PAGE_SHIFT #define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) #define PTE_MASK PAGE_MASK diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig index 455311d9a5e9..f32a1963ff0c 100644 --- a/arch/sh/mm/Kconfig +++ b/arch/sh/mm/Kconfig @@ -4,6 +4,9 @@ menu "Memory management options" config MMU bool "Support for memory management hardware" depends on !CPU_SH2 + select HAVE_PAGE_SIZE_4KB + select HAVE_PAGE_SIZE_8KB if X2TLB + select HAVE_PAGE_SIZE_64KB if CPU_SH4 default y help Some SH processors (such as SH-2/SH-2A) lack an MMU. In order to @@ -13,6 +16,15 @@ config MMU turning this off will boot the kernel on these machines with the MMU implicitly switched off. +config NOMMU + def_bool !MMU + select HAVE_PAGE_SIZE_4KB + select HAVE_PAGE_SIZE_8KB + select HAVE_PAGE_SIZE_16KB + select HAVE_PAGE_SIZE_64KB + help + On MMU-less systems, any of these page sizes can be selected + config PAGE_OFFSET hex default "0x80000000" if MMU @@ -147,36 +159,6 @@ config HAVE_SRAM_POOL bool select GENERIC_ALLOCATOR -choice - prompt "Kernel page size" - default PAGE_SIZE_4KB - -config PAGE_SIZE_4KB - bool "4kB" - help - This is the default page size used by all SuperH CPUs. - -config PAGE_SIZE_8KB - bool "8kB" - depends on !MMU || X2TLB - help - This enables 8kB pages as supported by SH-X2 and later MMUs. - -config PAGE_SIZE_16KB - bool "16kB" - depends on !MMU - help - This enables 16kB pages on MMU-less SH systems. - -config PAGE_SIZE_64KB - bool "64kB" - depends on !MMU || CPU_SH4 - help - This enables support for 64kB pages, possible on all SH-4 - CPUs and later. - -endchoice - choice prompt "HugeTLB page size" depends on HUGETLB_PAGE