Commit 4ca644d9 authored by Dave Hansen's avatar Dave Hansen Committed by Linus Torvalds
Browse files

[PATCH] memory hotplug prep: __section_nr helper 



A little helper that we use in the hotplug code.

Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ed8ece2e

include/linux/mmzone.h

+1 −0
Original line number Diff line number Diff line
@@ -509,6 +509,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) 
		return NULL;

	return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];

}

extern int __section_nr(struct mem_section* ms);



/*

 * We use the lower bits of the mem_map pointer to store

mm/sparse.c

+25 −0
Original line number Diff line number Diff line
@@ -72,6 +72,31 @@ static inline int sparse_index_init(unsigned long section_nr, int nid) 
}

#endif



/*

 * Although written for the SPARSEMEM_EXTREME case, this happens

 * to also work for the flat array case becase

 * NR_SECTION_ROOTS==NR_MEM_SECTIONS.

 */

int __section_nr(struct mem_section* ms)

{

	unsigned long root_nr;

	struct mem_section* root;



	for (root_nr = 0;

	     root_nr < NR_MEM_SECTIONS;

	     root_nr += SECTIONS_PER_ROOT) {

		root = __nr_to_section(root_nr);



		if (!root)

			continue;



		if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))

		     break;

	}



	return (root_nr * SECTIONS_PER_ROOT) + (ms - root);

}



/* Record a memory area against a node. */

void memory_present(int nid, unsigned long start, unsigned long end)

{

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