* Re: Can I change the kernel memory spliting in linux-2.4.25 + ?
2004-12-04 18:53 Fawad Lateef
2004-12-05 13:51 ` Jon Masters
@ 2004-12-05 16:01 ` Marc-Christian Petersen
1 sibling, 0 replies; 4+ messages in thread
From: Marc-Christian Petersen @ 2004-12-05 16:01 UTC (permalink / raw)
To: kernelnewbies; +Cc: Fawad Lateef, linux-mm
[-- Attachment #1: Type: text/plain, Size: 560 bytes --]
On Saturday 04 December 2004 19:53, Fawad Lateef wrote:
> Can I change the kernel memory spliting in
> linux-2.4.25 or onwards ??? Actually I want to change
> the kernel ZONE_NORMAL to 2GB from 1GB !!!!
sure you can :p
> How can i do this ??? I won't be able to see any
> option in kernel configuration ...........
because 2.4 does not have such options nor you wrote some in there ;)
> I tried to change the PAGE_OFFSET from 3G to 2G but
> got compilation error ..............
> What I hav to do ???
you may give attached patch a try.
--
ciao, Marc
[-- Attachment #2: 2.4.25-memsplit.patch --]
[-- Type: text/x-diff, Size: 11797 bytes --]
diff -Naurp linux-2.4.25/Documentation/Configure.help linux-2.4.25-memsplit/Documentation/Configure.help
--- linux-2.4.25/Documentation/Configure.help 2004-12-05 16:54:12.000000000 +0100
+++ linux-2.4.25-memsplit/Documentation/Configure.help 2004-12-05 17:00:41.000000000 +0100
@@ -406,6 +406,40 @@ CONFIG_HIGHMEM64G
Select this if you have a 32-bit processor and more than 4
gigabytes of physical RAM.
+User address space size
+CONFIG_05GB
+ If you have 4 Gigabytes of physical memory or less, you can change
+ where the kernel maps high memory.
+
+ Typically there will 128 megabytes less "user memory" mapped
+ than the number in the configuration option. Saying that
+ another way, "high memory" will usually start 128 megabytes
+ lower than the configuration option.
+
+ Selecting "05GB" results in a "3.5GB/0.5GB" kernel/user split.
+ On a system with 1 gigabyte of physical memory, you may get 384
+ megabytes of "user memory" and 640 megabytes of "high memory"
+ with this selection.
+
+ Selecting "1GB" results in a "3GB/1GB" kernel/user split.
+ On a system with 1 gigabyte of memory, you may get 896 MB of
+ "user memory" and 128 megabytes of "high memory" with this
+ selection. This is the usual setting.
+
+ Selecting "2GB" results in a "2GB/2GB" kernel/user split.
+ On a system with less than 1.75 gigabytes of physical memory,
+ this option will make it so no memory is mapped as "high".
+
+ Selecting "3GB" results in a "1GB/3GB" kernel/user split.
+
+ Select "1GB" otherwise Win4Lin and valgrind won't work!
+
+ Select "Real-1GB" to allocate even the last 128MB of RAM which
+ are normally mapped as high, but with this option mapped as low
+ without the need for enabling high memory support.
+
+ If unsure, say "1GB".
+
HIGHMEM I/O support
CONFIG_HIGHIO
If you want to be able to do I/O to high memory pages, say Y.
diff -Naurp linux-2.4.25/Rules.make linux-2.4.25-memsplit/Rules.make
--- linux-2.4.25/Rules.make 2004-02-18 14:36:30.000000000 +0100
+++ linux-2.4.25-memsplit/Rules.make 2004-12-05 16:56:55.000000000 +0100
@@ -215,6 +215,7 @@ MODINCL = $(TOPDIR)/include/linux/module
#
# 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
@@ -223,6 +224,22 @@ 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
+
$(MODINCL)/%.ver: %.c
@if [ ! -r $(MODINCL)/$*.stamp -o $(MODINCL)/$*.stamp -ot $< ]; then \
echo '$(CC) $(CFLAGS) $(EXTRA_CFLAGS_nostdinc) -E -D__GENKSYMS__ $<'; \
diff -Naurp linux-2.4.25/arch/i386/Makefile linux-2.4.25-memsplit/arch/i386/Makefile
--- linux-2.4.25/arch/i386/Makefile 2003-06-13 16:51:29.000000000 +0200
+++ linux-2.4.25-memsplit/arch/i386/Makefile 2004-12-05 16:56:55.000000000 +0100
@@ -114,6 +114,9 @@ arch/i386/mm: dummy
MAKEBOOT = $(MAKE) -C arch/$(ARCH)/boot
+arch/i386/vmlinux.lds: arch/i386/vmlinux.lds.S FORCE
+ $(CPP) -C -P -I$(HPATH) -imacros $(HPATH)/asm-i386/page_offset.h -Ui386 arch/i386/vmlinux.lds.S >arch/i386/vmlinux.lds
+
vmlinux: arch/i386/vmlinux.lds
FORCE: ;
@@ -150,6 +153,7 @@ archclean:
@$(MAKEBOOT) clean
archmrproper:
+ rm -f arch/i386/vmlinux.lds
archdep:
@$(MAKEBOOT) dep
diff -Naurp linux-2.4.25/arch/i386/config.in linux-2.4.25-memsplit/arch/i386/config.in
--- linux-2.4.25/arch/i386/config.in 2004-02-18 14:36:30.000000000 +0100
+++ linux-2.4.25-memsplit/arch/i386/config.in 2004-12-05 17:00:40.000000000 +0100
@@ -216,6 +216,18 @@ else
fi
if [ "$CONFIG_HIGHMEM64G" = "y" ]; then
define_bool CONFIG_X86_PAE y
+ choice 'User address space size' \
+ "3GB CONFIG_1GB \
+ 2GB CONFIG_2GB \
+ Real-1GB CONFIG_1GB_REAL \
+ 1GB CONFIG_3GB" 3GB
+else
+ choice 'User address space size' \
+ "3GB CONFIG_1GB \
+ 2GB CONFIG_2GB \
+ 1GB CONFIG_3GB \
+ Real-1GB CONFIG_1GB_REAL \
+ 3.5GB CONFIG_05GB" 3GB
fi
if [ "$CONFIG_HIGHMEM" = "y" ]; then
diff -Naurp linux-2.4.25/arch/i386/vmlinux.lds linux-2.4.25-memsplit/arch/i386/vmlinux.lds
--- linux-2.4.25/arch/i386/vmlinux.lds 2002-02-25 20:37:53.000000000 +0100
+++ linux-2.4.25-memsplit/arch/i386/vmlinux.lds 1970-01-01 01:00:00.000000000 +0100
@@ -1,82 +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)
-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 : { *(.initcall.init) }
- __initcall_end = .;
- . = ALIGN(4096);
- __init_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 -Naurp linux-2.4.25/arch/i386/vmlinux.lds.S linux-2.4.25-memsplit/arch/i386/vmlinux.lds.S
--- linux-2.4.25/arch/i386/vmlinux.lds.S 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.4.25-memsplit/arch/i386/vmlinux.lds.S 2004-12-05 16:56:55.000000000 +0100
@@ -0,0 +1,82 @@
+/* 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)
+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 : { *(.initcall.init) }
+ __initcall_end = .;
+ . = ALIGN(4096);
+ __init_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 -Naurp linux-2.4.25/include/asm-i386/page.h linux-2.4.25-memsplit/include/asm-i386/page.h
--- linux-2.4.25/include/asm-i386/page.h 2002-08-03 02:39:45.000000000 +0200
+++ linux-2.4.25-memsplit/include/asm-i386/page.h 2004-12-05 16:56:55.000000000 +0100
@@ -78,7 +78,9 @@ typedef struct { unsigned long pgprot; }
* 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 -Naurp linux-2.4.25/include/asm-i386/page_offset.h linux-2.4.25-memsplit/include/asm-i386/page_offset.h
--- linux-2.4.25/include/asm-i386/page_offset.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.4.25-memsplit/include/asm-i386/page_offset.h 2004-12-05 17:00:40.000000000 +0100
@@ -0,0 +1,12 @@
+#include <linux/config.h>
+#ifdef CONFIG_05GB
+# define PAGE_OFFSET_RAW 0xE0000000
+#elif defined(CONFIG_1GB)
+# define PAGE_OFFSET_RAW 0xC0000000
+#elif defined(CONFIG_1GB_REAL)
+# define PAGE_OFFSET_RAW 0xB0000000
+#elif defined(CONFIG_2GB)
+# define PAGE_OFFSET_RAW 0x80000000
+#elif defined(CONFIG_3GB)
+# define PAGE_OFFSET_RAW 0x40000000
+#endif
diff -Naurp linux-2.4.25/include/asm-i386/processor.h linux-2.4.25-memsplit/include/asm-i386/processor.h
--- linux-2.4.25/include/asm-i386/processor.h 2004-02-18 14:36:32.000000000 +0100
+++ linux-2.4.25-memsplit/include/asm-i386/processor.h 2004-12-05 16:56:55.000000000 +0100
@@ -264,7 +264,11 @@ extern unsigned int mca_pentium_flag;
/* 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 -Naurp linux-2.4.25/mm/memory.c linux-2.4.25-memsplit/mm/memory.c
--- linux-2.4.25/mm/memory.c 2003-11-28 19:26:21.000000000 +0100
+++ linux-2.4.25-memsplit/mm/memory.c 2004-12-05 16:56:55.000000000 +0100
@@ -108,8 +108,7 @@ static inline void free_one_pmd(pmd_t *
static inline void free_one_pgd(pgd_t * dir)
{
- int j;
- pmd_t * pmd;
+ pmd_t * pmd, * md, * emd;
if (pgd_none(*dir))
return;
@@ -120,9 +119,23 @@ static inline void free_one_pgd(pgd_t *
}
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(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(md);
}
pmd_free(pmd);
}
^ permalink raw reply [flat|nested] 4+ messages in thread