__section_nr() was used to convert struct mem_section * to section_nr.
With CONFIG_SPARSEMEM_EXTREME enabled, however, __section_nr() can be
costly since it iterates all section roots to check if the given
mem_section is in its range.
On the other hand, __nr_to_section() which converts section_nr to
mem_section can be done in O(1).
The only users of __section_nr() was section_mark_present() and
find_memory_block().
Since I changed both functions to use section_nr directly in the
preceeding patches, let's remove __section_nr() which has no users.
Signed-off-by: Ohhoon Kwon <ohoono.kwon@xxxxxxxxxxx>
---
include/linux/mmzone.h | 1 -
mm/sparse.c | 26 --------------------------
2 files changed, 27 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0d53eba1c383..8931f95cf885 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1321,7 +1321,6 @@ 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 unsigned long __section_nr(struct mem_section *ms);
extern size_t mem_section_usage_size(void);
/*
diff --git a/mm/sparse.c b/mm/sparse.c
index 4a2700e9a65f..1b32d15593e4 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -108,32 +108,6 @@ static inline int sparse_index_init(unsigned long section_nr, int nid)
}
#endif
-#ifdef CONFIG_SPARSEMEM_EXTREME
-unsigned long __section_nr(struct mem_section *ms)
-{
- unsigned long root_nr;
- struct mem_section *root = NULL;
-
- for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
- root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
- if (!root)
- continue;
-
- if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
- break;
- }
-
- VM_BUG_ON(!root);
-
- return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
-}
-#else
-unsigned long __section_nr(struct mem_section *ms)
-{
- return (unsigned long)(ms - mem_section[0]);
-}
-#endif
-
/*
* During early boot, before section_mem_map is used for an actual
* mem_map, we use section_mem_map to store the section's NUMA
--
2.17.1
