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Commit e8eff5ac authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

[PATCH] Make swsusp avoid memory holes and reserved memory regions on x86_64 



On x86_64 machines with more than 2 GB of RAM there are large memory gaps
(with no corresponding kernel virtual addresses) and reserved memory
regions between areas of usable physical RAM.  Moreover, if CONFIG_FLATMEM
is set, they appear within the normal zone.  swsusp should not try to save
them, so the corresponding page structs have to be marked as 'nosave'.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent fb13a28b

arch/x86_64/kernel/e820.c

+48 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/string.h>

#include <linux/kexec.h>

#include <linux/module.h>

#include <linux/mm.h>



#include <asm/pgtable.h>

#include <asm/page.h>
@@ -297,6 +298,53 @@ void __init e820_reserve_resources(void) 
	}

}



/* Mark pages corresponding to given address range as nosave */

static void __init

e820_mark_nosave_range(unsigned long start, unsigned long end)

{

	unsigned long pfn, max_pfn;



	if (start >= end)

		return;



	printk("Nosave address range: %016lx - %016lx\n", start, end);

	max_pfn = end >> PAGE_SHIFT;

	for (pfn = start >> PAGE_SHIFT; pfn < max_pfn; pfn++)

		if (pfn_valid(pfn))

			SetPageNosave(pfn_to_page(pfn));

}



/*

 * Find the ranges of physical addresses that do not correspond to

 * e820 RAM areas and mark the corresponding pages as nosave for software

 * suspend and suspend to RAM.

 *

 * This function requires the e820 map to be sorted and without any

 * overlapping entries and assumes the first e820 area to be RAM.

 */

void __init e820_mark_nosave_regions(void)

{

	int i;

	unsigned long paddr;



	paddr = round_down(e820.map[0].addr + e820.map[0].size, PAGE_SIZE);

	for (i = 1; i < e820.nr_map; i++) {

		struct e820entry *ei = &e820.map[i];



		if (paddr < ei->addr)

			e820_mark_nosave_range(paddr,

					round_up(ei->addr, PAGE_SIZE));



		paddr = round_down(ei->addr + ei->size, PAGE_SIZE);

		if (ei->type != E820_RAM)

			e820_mark_nosave_range(round_up(ei->addr, PAGE_SIZE),

					paddr);



		if (paddr >= (end_pfn << PAGE_SHIFT))

			break;

	}

}



/* 

 * Add a memory region to the kernel e820 map.

 */

arch/x86_64/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -689,6 +689,7 @@ void __init setup_arch(char **cmdline_p) 
	 */

	probe_roms();

	e820_reserve_resources(); 

	e820_mark_nosave_regions();



	request_resource(&iomem_resource, &video_ram_resource);

include/asm-x86_64/e820.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ extern void setup_memory_region(void); 
extern void contig_e820_setup(void); 

extern unsigned long e820_end_of_ram(void);

extern void e820_reserve_resources(void);

extern void e820_mark_nosave_regions(void);

extern void e820_print_map(char *who);

extern int e820_any_mapped(unsigned long start, unsigned long end, unsigned type);

extern int e820_all_mapped(unsigned long start, unsigned long end, unsigned type);