Commit 9d99aaa3 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

[PATCH] x86_64: Support memory hotadd without sparsemem 



Memory hotadd doesn't need SPARSEMEM, but can be handled by just preallocating
mem_maps. This only needs some untangling of ifdefs to enable the necessary
code even without SPARSEMEM.

Originally from Keith Mannthey, hacked by AK.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 805e8c03

arch/i386/mm/init.c

+2 −0
Original line number Diff line number Diff line
@@ -651,6 +651,7 @@ void __init mem_init(void) 
 * Specifically, in the case of x86, we will always add

 * memory to the highmem for now.

 */

#ifdef CONFIG_HOTPLUG_MEMORY

#ifndef CONFIG_NEED_MULTIPLE_NODES

int add_memory(u64 start, u64 size)

{
@@ -667,6 +668,7 @@ int remove_memory(u64 start, u64 size) 
	return -EINVAL;

}

#endif

#endif



kmem_cache_t *pgd_cache;

kmem_cache_t *pmd_cache;

arch/x86_64/kernel/e820.c

+1 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ static inline int bad_addr(unsigned long *addrp, unsigned long size) 
	return 0;

} 



int __init e820_mapped(unsigned long start, unsigned long end, unsigned type) 

int __meminit e820_mapped(unsigned long start, unsigned long end, unsigned type)

{ 

	int i;

	for (i = 0; i < e820.nr_map; i++) {

arch/x86_64/mm/init.c

+34 −2
Original line number Diff line number Diff line
@@ -507,9 +507,8 @@ void __init clear_kernel_mapping(unsigned long address, unsigned long size) 


/*

 * Memory hotplug specific functions

 * These are only for non-NUMA machines right now.

 */

#ifdef CONFIG_MEMORY_HOTPLUG

#if defined(CONFIG_ACPI_HOTPLUG_MEMORY) || defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)



void online_page(struct page *page)

{
@@ -520,6 +519,39 @@ void online_page(struct page *page) 
	num_physpages++;

}



#ifndef CONFIG_MEMORY_HOTPLUG

/*

 * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,

 * just online the pages.

 */

int __add_pages(struct zone *z, unsigned long start_pfn, unsigned long nr_pages)

{

	int err = -EIO;

	unsigned long pfn;

	unsigned long total = 0, mem = 0;

	for (pfn = start_pfn; pfn < start_pfn + nr_pages; pfn++) {

		unsigned long addr = pfn << PAGE_SHIFT;

		if (pfn_valid(pfn) && e820_mapped(addr, addr+1, E820_RAM)) {

			online_page(pfn_to_page(pfn));

			err = 0;

			mem++;

		}

		total++;

	}

	if (!err) {

		z->spanned_pages += total;

		z->present_pages += mem;

		z->zone_pgdat->node_spanned_pages += total;

		z->zone_pgdat->node_present_pages += mem;

	}

	return err;

}

#endif



/*

 * Memory is added always to NORMAL zone. This means you will never get

 * additional DMA/DMA32 memory.

 */

int add_memory(u64 start, u64 size)

{

	struct pglist_data *pgdat = NODE_DATA(0);

drivers/acpi/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -329,7 +329,7 @@ config ACPI_CONTAINER 
config ACPI_HOTPLUG_MEMORY

	tristate "Memory Hotplug"

	depends on ACPI

	depends on MEMORY_HOTPLUG

	depends on MEMORY_HOTPLUG || X86_64

	default n

	help

	  This driver adds supports for ACPI Memory Hotplug.  This driver

include/linux/init.h

+2 −1
Original line number Diff line number Diff line
@@ -245,7 +245,8 @@ void __init parse_early_param(void); 
#define __cpuexitdata	__exitdata

#endif



#ifdef CONFIG_MEMORY_HOTPLUG

#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_ACPI_HOTPLUG_MEMORY) \

	|| defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)

#define __meminit

#define __meminitdata

#define __memexit

CRA Git | Maintained and supported by SUSTech CRA and CCSE