Whether they're a user that is doing a scientific application that
needs more than 3GB, or a large PAE machine that needs more
ZONE_NORMAL, lots of people are applying patches to change
PAGE_OFFSET. This patch lets you do it in a config option. It is a
port from Andrea's 2.4 tree, and I believe that Ingo is the original
author.
Andrea's patch didn't have a Config.help entry for this option, so I
wrote one. I may not have all of the necessary context to explain it,
so any comments there would be appreciated.
-- Dave Hansen haveblue@us.ibm.com--------------030205050609010707080408 Content-Type: text/plain; name="page_offset-config-2.5.31+bk-0.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="page_offset-config-2.5.31+bk-0.patch"
# This is a BitKeeper generated patch for the following project: # Project Name: Linux kernel tree # This patch format is intended for GNU patch command version 2.5 or higher. # This patch includes the following deltas: # ChangeSet 1.489 -> 1.491 # include/asm-i386/processor.h 1.28 -> 1.29 # arch/i386/Config.help 1.12 -> 1.13 # include/asm-i386/page.h 1.15 -> 1.16 # arch/i386/vmlinux.lds 1.9 -> (deleted) # arch/i386/config.in 1.46 -> 1.47 # arch/i386/Makefile 1.16 -> 1.17 # Rules.make 1.68 -> 1.69 # mm/memory.c 1.83 -> 1.85 # (new) -> 1.1 arch/i386/vmlinux.lds.S # (new) -> 1.1 include/asm-i386/page_offset.h # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/08/19 haveblue@elm3b96.(none) 1.490 # merge Andrea's PAGE_OFFSET configuration option # -------------------------------------------- # 02/08/19 haveblue@elm3b96.(none) 1.491 # fix merge bug # # add Config.help entry # -------------------------------------------- # diff -Nru a/Rules.make b/Rules.make --- a/Rules.make Mon Aug 19 13:28:19 2002 +++ b/Rules.make Mon Aug 19 13:28:19 2002 @@ -149,12 +149,29 @@ # # Added the SMP separator to stop module accidents between uniprocessor # and SMP Intel boxes - AC - from bits by Michael Chastain +# Added separator for different PAGE_OFFSET memory models - Ingo. # ifdef CONFIG_SMP genksyms_smp_prefix := -p smp_ else genksyms_smp_prefix := +endif + +ifdef CONFIG_2GB +ifdef CONFIG_SMP + genksyms_smp_prefix := -p smp_2gig_ +else + genksyms_smp_prefix := -p 2gig_ +endif +endif + +ifdef CONFIG_3GB +ifdef CONFIG_SMP + genksyms_smp_prefix := -p smp_3gig_ +else + genksyms_smp_prefix := -p 3gig_ +endif endif # Don't include modversions.h, we're just about to generate it here. diff -Nru a/arch/i386/Config.help b/arch/i386/Config.help --- a/arch/i386/Config.help Mon Aug 19 13:28:19 2002 +++ b/arch/i386/Config.help Mon Aug 19 13:28:19 2002 @@ -128,6 +128,27 @@ If unsure, say "off". +CONFIG_1GB + On i386, a process can only virtually address 4GB of memory. This + lets you select how much of that virtual space you would like to + devoted to userspace, and how much to the kernel. + + Some userspace programs would like to address as much as possible and + have few demands of the kernel other than it get out of the way. These + users may opt to use the 3.5GB option to give their userspace program + as much room as possible. Due to alignment issues imposed by PAE, + the "3.5GB" option is unavailable if "64GB" high memory support is + enabled. + + Other users (especially those who use PAE) may be running out of + ZONE_NORMAL memory. Those users may benefit from increasing the + kernel's virtual address space size by taking it away from userspace, + which may not need all of its space. An indicator that this is + happening is when /proc/Meminfo's "LowFree:" is a small percentage of + "LowTotal:" while "HighFree:" is very large. + + If unsure, say "3GB" + CONFIG_HIGHPTE The VM uses one page table entry for each page of physical memory. For systems with a lot of RAM, this can be wasteful of precious diff -Nru a/arch/i386/Makefile b/arch/i386/Makefile --- a/arch/i386/Makefile Mon Aug 19 13:28:19 2002 +++ b/arch/i386/Makefile Mon Aug 19 13:28:19 2002 @@ -104,6 +104,9 @@ MAKEBOOT = +$(MAKE) -C arch/$(ARCH)/boot +arch/i386/vmlinux.lds: arch/i386/vmlinux.lds.S FORCE + $(CPP) -C -P -I$(HPATH) -imacros $(HPATH)/asm-i386/page_offset.h -Ui386 arch/i386/vmlinux.lds.S >arch/i386/vmlinux.lds + vmlinux: arch/i386/vmlinux.lds .PHONY: zImage bzImage compressed zlilo bzlilo zdisk bzdisk install \ @@ -141,3 +144,4 @@ @$(MAKEBOOT) clean archmrproper: + rm -f arch/i386/vmlinux.lds diff -Nru a/arch/i386/config.in b/arch/i386/config.in --- a/arch/i386/config.in Mon Aug 19 13:28:19 2002 +++ b/arch/i386/config.in Mon Aug 19 13:28:19 2002 @@ -186,14 +186,24 @@ 4GB CONFIG_HIGHMEM4G \ 64GB CONFIG_HIGHMEM64G" off -if [ "$CONFIG_HIGHMEM4G" = "y" ]; then +if [ "$CONFIG_HIGHMEM4G" = "y" -o "$CONFIG_HIGHMEM64G" = "y" ]; then define_bool CONFIG_HIGHMEM y fi if [ "$CONFIG_HIGHMEM64G" = "y" ]; then - define_bool CONFIG_HIGHMEM y define_bool CONFIG_X86_PAE y + choice 'User address space size' \ + "3GB CONFIG_1GB \ + 2GB CONFIG_2GB \ + 1GB CONFIG_3GB" 3GB +else + choice 'User address space size' \ + "3GB CONFIG_1GB \ + 2GB CONFIG_2GB \ + 1GB CONFIG_3GB \ + 3.5GB CONFIG_05GB" 3GB fi + bool 'Math emulation' CONFIG_MATH_EMULATION bool 'MTRR (Memory Type Range Register) support' CONFIG_MTRR diff -Nru a/arch/i386/vmlinux.lds b/arch/i386/vmlinux.lds --- a/arch/i386/vmlinux.lds Mon Aug 19 13:28:19 2002 +++ /dev/null Wed Dec 31 16:00:00 1969 @@ -1,101 +0,0 @@ -/* ld script to make i386 Linux kernel - * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>; - */ -OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") -OUTPUT_ARCH(i386) -ENTRY(_start) -jiffies = jiffies_64; -SECTIONS -{ - . = 0xC0000000 + 0x100000; - _text = .; /* Text and read-only data */ - .text : { - *(.text) - *(.fixup) - *(.gnu.warning) - } = 0x9090 - - _etext = .; /* End of text section */ - - .rodata : { *(.rodata) *(.rodata.*) } - .kstrtab : { *(.kstrtab) } - - . = ALIGN(16); /* Exception table */ - __start___ex_table = .; - __ex_table : { *(__ex_table) } - __stop___ex_table = .; - - __start___ksymtab = .; /* Kernel symbol table */ - __ksymtab : { *(__ksymtab) } - __stop___ksymtab = .; - - .data : { /* Data */ - *(.data) - CONSTRUCTORS - } - - _edata = .; /* End of data section */ - - . = ALIGN(8192); /* init_task */ - .data.init_task : { *(.data.init_task) } - - . = ALIGN(4096); /* Init code and data */ - __init_begin = .; - .text.init : { *(.text.init) } - .data.init : { *(.data.init) } - . = ALIGN(16); - __setup_start = .; - .setup.init : { *(.setup.init) } - __setup_end = .; - __initcall_start = .; - .initcall.init : { - *(.initcall1.init) - *(.initcall2.init) - *(.initcall3.init) - *(.initcall4.init) - *(.initcall5.init) - *(.initcall6.init) - *(.initcall7.init) - } - __initcall_end = .; - . = ALIGN(32); - __per_cpu_start = .; - .data.percpu : { *(.data.percpu) } - __per_cpu_end = .; - . = ALIGN(4096); - __init_end = .; - - . = ALIGN(4096); - __nosave_begin = .; - .data_nosave : { *(.data.nosave) } - . = ALIGN(4096); - __nosave_end = .; - - . = ALIGN(4096); - .data.page_aligned : { *(.data.idt) } - - . = ALIGN(32); - .data.cacheline_aligned : { *(.data.cacheline_aligned) } - - __bss_start = .; /* BSS */ - .bss : { - *(.bss) - } - _end = . ; - - /* Sections to be discarded */ - /DISCARD/ : { - *(.text.exit) - *(.data.exit) - *(.exitcall.exit) - } - - /* Stabs debugging sections. */ - .stab 0 : { *(.stab) } - .stabstr 0 : { *(.stabstr) } - .stab.excl 0 : { *(.stab.excl) } - .stab.exclstr 0 : { *(.stab.exclstr) } - .stab.index 0 : { *(.stab.index) } - .stab.indexstr 0 : { *(.stab.indexstr) } - .comment 0 : { *(.comment) } -} diff -Nru a/arch/i386/vmlinux.lds.S b/arch/i386/vmlinux.lds.S --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/arch/i386/vmlinux.lds.S Mon Aug 19 13:28:19 2002 @@ -0,0 +1,101 @@ +/* ld script to make i386 Linux kernel + * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>; + */ +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(_start) +jiffies = jiffies_64; +SECTIONS +{ + . = PAGE_OFFSET_RAW + 0x100000; + _text = .; /* Text and read-only data */ + .text : { + *(.text) + *(.fixup) + *(.gnu.warning) + } = 0x9090 + + _etext = .; /* End of text section */ + + .rodata : { *(.rodata) *(.rodata.*) } + .kstrtab : { *(.kstrtab) } + + . = ALIGN(16); /* Exception table */ + __start___ex_table = .; + __ex_table : { *(__ex_table) } + __stop___ex_table = .; + + __start___ksymtab = .; /* Kernel symbol table */ + __ksymtab : { *(__ksymtab) } + __stop___ksymtab = .; + + .data : { /* Data */ + *(.data) + CONSTRUCTORS + } + + _edata = .; /* End of data section */ + + . = ALIGN(8192); /* init_task */ + .data.init_task : { *(.data.init_task) } + + . = ALIGN(4096); /* Init code and data */ + __init_begin = .; + .text.init : { *(.text.init) } + .data.init : { *(.data.init) } + . = ALIGN(16); + __setup_start = .; + .setup.init : { *(.setup.init) } + __setup_end = .; + __initcall_start = .; + .initcall.init : { + *(.initcall1.init) + *(.initcall2.init) + *(.initcall3.init) + *(.initcall4.init) + *(.initcall5.init) + *(.initcall6.init) + *(.initcall7.init) + } + __initcall_end = .; + . = ALIGN(32); + __per_cpu_start = .; + .data.percpu : { *(.data.percpu) } + __per_cpu_end = .; + . = ALIGN(4096); + __init_end = .; + + . = ALIGN(4096); + __nosave_begin = .; + .data_nosave : { *(.data.nosave) } + . = ALIGN(4096); + __nosave_end = .; + + . = ALIGN(4096); + .data.page_aligned : { *(.data.idt) } + + . = ALIGN(32); + .data.cacheline_aligned : { *(.data.cacheline_aligned) } + + __bss_start = .; /* BSS */ + .bss : { + *(.bss) + } + _end = . ; + + /* Sections to be discarded */ + /DISCARD/ : { + *(.text.exit) + *(.data.exit) + *(.exitcall.exit) + } + + /* Stabs debugging sections. */ + .stab 0 : { *(.stab) } + .stabstr 0 : { *(.stabstr) } + .stab.excl 0 : { *(.stab.excl) } + .stab.exclstr 0 : { *(.stab.exclstr) } + .stab.index 0 : { *(.stab.index) } + .stab.indexstr 0 : { *(.stab.indexstr) } + .comment 0 : { *(.comment) } +} diff -Nru a/include/asm-i386/page.h b/include/asm-i386/page.h --- a/include/asm-i386/page.h Mon Aug 19 13:28:19 2002 +++ b/include/asm-i386/page.h Mon Aug 19 13:28:19 2002 @@ -81,7 +81,9 @@ * and CONFIG_HIGHMEM64G options in the kernel configuration. */ -#define __PAGE_OFFSET (0xC0000000) +#include <asm/page_offset.h> + +#define __PAGE_OFFSET (PAGE_OFFSET_RAW) /* * This much address space is reserved for vmalloc() and iomap() diff -Nru a/include/asm-i386/page_offset.h b/include/asm-i386/page_offset.h --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/include/asm-i386/page_offset.h Mon Aug 19 13:28:19 2002 @@ -0,0 +1,10 @@ +#include <linux/config.h> +#ifdef CONFIG_05GB +#define PAGE_OFFSET_RAW 0xE0000000 +#elif defined(CONFIG_1GB) +#define PAGE_OFFSET_RAW 0xC0000000 +#elif defined(CONFIG_2GB) +#define PAGE_OFFSET_RAW 0x80000000 +#elif defined(CONFIG_3GB) +#define PAGE_OFFSET_RAW 0x40000000 +#endif diff -Nru a/include/asm-i386/processor.h b/include/asm-i386/processor.h --- a/include/asm-i386/processor.h Mon Aug 19 13:28:19 2002 +++ b/include/asm-i386/processor.h Mon Aug 19 13:28:19 2002 @@ -270,7 +270,11 @@ /* This decides where the kernel will search for a free chunk of vm * space during mmap's. */ +#ifndef CONFIG_05GB #define TASK_UNMAPPED_BASE (TASK_SIZE / 3) +#else +#define TASK_UNMAPPED_BASE (TASK_SIZE / 16) +#endif /* * Size of io_bitmap in longwords: 32 is ports 0-0x3ff. diff -Nru a/mm/memory.c b/mm/memory.c --- a/mm/memory.c Mon Aug 19 13:28:19 2002 +++ b/mm/memory.c Mon Aug 19 13:28:19 2002 @@ -97,8 +97,7 @@ static inline void free_one_pgd(mmu_gather_t *tlb, pgd_t * dir) { - int j; - pmd_t * pmd; + pmd_t * pmd, * md, * emd; if (pgd_none(*dir)) return; @@ -109,9 +108,23 @@ } pmd = pmd_offset(dir, 0); pgd_clear(dir); - for (j = 0; j < PTRS_PER_PMD ; j++) { - prefetchw(pmd+j+(PREFETCH_STRIDE/16)); - free_one_pmd(tlb, pmd+j); + + /* + * Beware if changing the loop below. It once used int j, + * for (j = 0; j < PTRS_PER_PMD; j++) + * free_one_pmd(pmd+j); + * but some older i386 compilers (e.g. egcs-2.91.66, gcc-2.95.3) + * terminated the loop with a _signed_ address comparison + * using "jle", when configured for HIGHMEM64GB (X86_PAE). + * If also configured for 3GB of kernel virtual address space, + * if page at physical 0x3ffff000 virtual 0x7ffff000 is used as + * a pmd, when that mm exits the loop goes on to free "entries" + * found at 0x80000000 onwards. The loop below compiles instead + * to be terminated by unsigned address comparison using "jb". + */ + for (md = pmd, emd = pmd + PTRS_PER_PMD; md < emd; md++) { + prefetchw(md+(PREFETCH_STRIDE/16)); + free_one_pmd(tlb,md); } pmd_free_tlb(tlb, pmd); }
--------------030205050609010707080408--
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