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| author | Zhou Chengming <zhouchengming1@huawei.com> | 2016-07-28 15:48:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 16:07:41 -0700 |
| commit | 91fd8b95d656dcd3f0a4e17b6583e7b0220b0747 (patch) | |
| tree | 8e33bf623881a0471ff611f3176f603cc27efe7d /mm | |
| parent | 98c42d945238c55ab56e5716e89553fb7de45b66 (diff) | |
| download | linux-91fd8b95d656dcd3f0a4e17b6583e7b0220b0747.tar.gz | |
make __section_nr() more efficient
When CONFIG_SPARSEMEM_EXTREME is disabled, __section_nr can get the
section number with a subtraction directly.
Link: http://lkml.kernel.org/r/1468988310-11560-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/sparse.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/mm/sparse.c b/mm/sparse.c index 5d0cf4540364..36d7bbb80e49 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -100,11 +100,7 @@ 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 because - * NR_SECTION_ROOTS==NR_MEM_SECTIONS. - */ +#ifdef CONFIG_SPARSEMEM_EXTREME int __section_nr(struct mem_section* ms) { unsigned long root_nr; @@ -123,6 +119,12 @@ int __section_nr(struct mem_section* ms) return (root_nr * SECTIONS_PER_ROOT) + (ms - root); } +#else +int __section_nr(struct mem_section* ms) +{ + return (int)(ms - mem_section[0]); +} +#endif /* * During early boot, before section_mem_map is used for an actual |