5c755e9fd8
Memory may be hot-removed on a per-memory-block basis, particularly on POWER where the SPARSEMEM section size often matches the memory-block size. A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation. This patch adds a file called "removable" to the memory directory in sysfs to help such an agent. In this patch, a memory block is considered removable if; o It contains only MOVABLE pageblocks o It contains only pageblocks with free pages regardless of pageblock type On the other hand, a memory block starting with a PageReserved() page will never be considered removable. Without this patch, the user-agent is forced to choose a memory block to remove randomly. Sample output of the sysfs files: ./memory/memory0/removable: 0 ./memory/memory1/removable: 0 ./memory/memory2/removable: 0 ./memory/memory3/removable: 0 ./memory/memory4/removable: 0 ./memory/memory5/removable: 0 ./memory/memory6/removable: 0 ./memory/memory7/removable: 1 ./memory/memory8/removable: 0 ./memory/memory9/removable: 0 ./memory/memory10/removable: 0 ./memory/memory11/removable: 0 ./memory/memory12/removable: 0 ./memory/memory13/removable: 0 ./memory/memory14/removable: 0 ./memory/memory15/removable: 0 ./memory/memory16/removable: 0 ./memory/memory17/removable: 1 ./memory/memory18/removable: 1 ./memory/memory19/removable: 1 ./memory/memory20/removable: 1 ./memory/memory21/removable: 1 ./memory/memory22/removable: 1 Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
223 lines
6.3 KiB
C
223 lines
6.3 KiB
C
#ifndef __LINUX_MEMORY_HOTPLUG_H
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#define __LINUX_MEMORY_HOTPLUG_H
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#include <linux/mmzone.h>
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#include <linux/spinlock.h>
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#include <linux/notifier.h>
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struct page;
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struct zone;
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struct pglist_data;
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struct mem_section;
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#ifdef CONFIG_MEMORY_HOTPLUG
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/*
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* Types for free bootmem.
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* The normal smallest mapcount is -1. Here is smaller value than it.
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*/
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#define SECTION_INFO (-1 - 1)
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#define MIX_SECTION_INFO (-1 - 2)
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#define NODE_INFO (-1 - 3)
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/*
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* pgdat resizing functions
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*/
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static inline
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void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
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{
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spin_lock_irqsave(&pgdat->node_size_lock, *flags);
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}
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static inline
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void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
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{
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spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
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}
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static inline
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void pgdat_resize_init(struct pglist_data *pgdat)
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{
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spin_lock_init(&pgdat->node_size_lock);
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}
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/*
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* Zone resizing functions
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*/
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static inline unsigned zone_span_seqbegin(struct zone *zone)
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{
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return read_seqbegin(&zone->span_seqlock);
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}
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static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
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{
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return read_seqretry(&zone->span_seqlock, iv);
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}
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static inline void zone_span_writelock(struct zone *zone)
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{
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write_seqlock(&zone->span_seqlock);
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}
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static inline void zone_span_writeunlock(struct zone *zone)
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{
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write_sequnlock(&zone->span_seqlock);
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}
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static inline void zone_seqlock_init(struct zone *zone)
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{
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seqlock_init(&zone->span_seqlock);
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}
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extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
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extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
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extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
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/* need some defines for these for archs that don't support it */
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extern void online_page(struct page *page);
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/* VM interface that may be used by firmware interface */
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extern int online_pages(unsigned long, unsigned long);
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extern void __offline_isolated_pages(unsigned long, unsigned long);
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extern int offline_pages(unsigned long, unsigned long, unsigned long);
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/* reasonably generic interface to expand the physical pages in a zone */
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extern int __add_pages(struct zone *zone, unsigned long start_pfn,
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unsigned long nr_pages);
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extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
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unsigned long nr_pages);
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#ifdef CONFIG_NUMA
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extern int memory_add_physaddr_to_nid(u64 start);
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#else
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static inline int memory_add_physaddr_to_nid(u64 start)
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{
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return 0;
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}
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#endif
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#ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
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/*
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* For supporting node-hotadd, we have to allocate a new pgdat.
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*
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* If an arch has generic style NODE_DATA(),
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* node_data[nid] = kzalloc() works well. But it depends on the architecture.
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*
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* In general, generic_alloc_nodedata() is used.
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* Now, arch_free_nodedata() is just defined for error path of node_hot_add.
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*
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*/
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extern pg_data_t *arch_alloc_nodedata(int nid);
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extern void arch_free_nodedata(pg_data_t *pgdat);
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extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
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#else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
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#define arch_alloc_nodedata(nid) generic_alloc_nodedata(nid)
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#define arch_free_nodedata(pgdat) generic_free_nodedata(pgdat)
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#ifdef CONFIG_NUMA
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/*
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* If ARCH_HAS_NODEDATA_EXTENSION=n, this func is used to allocate pgdat.
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* XXX: kmalloc_node() can't work well to get new node's memory at this time.
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* Because, pgdat for the new node is not allocated/initialized yet itself.
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* To use new node's memory, more consideration will be necessary.
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*/
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#define generic_alloc_nodedata(nid) \
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({ \
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kzalloc(sizeof(pg_data_t), GFP_KERNEL); \
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})
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/*
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* This definition is just for error path in node hotadd.
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* For node hotremove, we have to replace this.
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*/
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#define generic_free_nodedata(pgdat) kfree(pgdat)
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extern pg_data_t *node_data[];
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static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
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{
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node_data[nid] = pgdat;
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}
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#else /* !CONFIG_NUMA */
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/* never called */
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static inline pg_data_t *generic_alloc_nodedata(int nid)
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{
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BUG();
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return NULL;
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}
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static inline void generic_free_nodedata(pg_data_t *pgdat)
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{
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}
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static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
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{
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}
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#endif /* CONFIG_NUMA */
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#endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
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#ifdef CONFIG_SPARSEMEM_VMEMMAP
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static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
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{
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}
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static inline void put_page_bootmem(struct page *page)
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{
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}
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#else
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extern void register_page_bootmem_info_node(struct pglist_data *pgdat);
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extern void put_page_bootmem(struct page *page);
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#endif
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#else /* ! CONFIG_MEMORY_HOTPLUG */
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/*
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* Stub functions for when hotplug is off
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*/
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static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
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static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
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static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
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static inline unsigned zone_span_seqbegin(struct zone *zone)
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{
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return 0;
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}
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static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
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{
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return 0;
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}
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static inline void zone_span_writelock(struct zone *zone) {}
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static inline void zone_span_writeunlock(struct zone *zone) {}
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static inline void zone_seqlock_init(struct zone *zone) {}
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static inline int mhp_notimplemented(const char *func)
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{
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printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
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dump_stack();
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return -ENOSYS;
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}
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static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
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{
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}
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#endif /* ! CONFIG_MEMORY_HOTPLUG */
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/*
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* Walk through all memory which is registered as resource.
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* arg is (start_pfn, nr_pages, private_arg_pointer)
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*/
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extern int walk_memory_resource(unsigned long start_pfn,
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unsigned long nr_pages, void *arg,
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int (*func)(unsigned long, unsigned long, void *));
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#ifdef CONFIG_MEMORY_HOTREMOVE
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extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
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#else
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static inline int is_mem_section_removable(unsigned long pfn,
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unsigned long nr_pages)
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{
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return 0;
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}
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#endif /* CONFIG_MEMORY_HOTREMOVE */
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extern int add_memory(int nid, u64 start, u64 size);
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extern int arch_add_memory(int nid, u64 start, u64 size);
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extern int remove_memory(u64 start, u64 size);
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extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
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int nr_pages);
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extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
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extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
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unsigned long pnum);
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#endif /* __LINUX_MEMORY_HOTPLUG_H */
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