diff options
| -rw-r--r-- | include/linux/mmzone.h | 1 | ||||
| -rw-r--r-- | mm/sparse.c | 25 |
2 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7519eb4191e7..4674145bb63d 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -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 diff --git a/mm/sparse.c b/mm/sparse.c index 347249a4917a..0d3bd4bf3aaa 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -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) { |