mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
485761bd6a
Some nodes can have large holes on x86-64. This fixes problems with the VM allowing too many dirty pages because it overestimates the number of available RAM in a node. In extreme cases you can end up with all RAM filled with dirty pages which can lead to deadlocks and other nasty behaviour. This patch just tells the VM about the known holes from e820. Reserved (like the kernel text or mem_map) is still not taken into account, but that should be only a few percent error now. Small detail is that the flat setup uses the NUMA free_area_init_node() now too because it offers more flexibility. (akpm: lotsa thanks to Martin for working this problem out) Cc: Martin Bligh <mbligh@mbligh.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
/*
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* structures and definitions for the int 15, ax=e820 memory map
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* scheme.
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*
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* In a nutshell, setup.S populates a scratch table in the
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* empty_zero_block that contains a list of usable address/size
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* duples. setup.c, this information is transferred into the e820map,
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* and in init.c/numa.c, that new information is used to mark pages
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* reserved or not.
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*/
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#ifndef __E820_HEADER
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#define __E820_HEADER
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#include <linux/mmzone.h>
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#define E820MAP 0x2d0 /* our map */
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#define E820MAX 128 /* number of entries in E820MAP */
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#define E820NR 0x1e8 /* # entries in E820MAP */
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#define E820_RAM 1
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#define E820_RESERVED 2
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#define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */
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#define E820_NVS 4
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#define HIGH_MEMORY (1024*1024)
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#define LOWMEMSIZE() (0x9f000)
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#ifndef __ASSEMBLY__
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struct e820entry {
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u64 addr; /* start of memory segment */
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u64 size; /* size of memory segment */
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u32 type; /* type of memory segment */
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} __attribute__((packed));
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struct e820map {
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int nr_map;
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struct e820entry map[E820MAX];
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};
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extern unsigned long find_e820_area(unsigned long start, unsigned long end,
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unsigned size);
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extern void add_memory_region(unsigned long start, unsigned long size,
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int type);
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extern void setup_memory_region(void);
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extern void contig_e820_setup(void);
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extern unsigned long e820_end_of_ram(void);
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extern void e820_reserve_resources(void);
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extern void e820_print_map(char *who);
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extern int e820_mapped(unsigned long start, unsigned long end, unsigned type);
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extern void e820_bootmem_free(pg_data_t *pgdat, unsigned long start,unsigned long end);
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extern void e820_setup_gap(void);
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extern unsigned long e820_hole_size(unsigned long start_pfn,
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unsigned long end_pfn);
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extern void __init parse_memopt(char *p, char **end);
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extern struct e820map e820;
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#endif/*!__ASSEMBLY__*/
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#endif/*__E820_HEADER*/
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