Commit 60a7a88d authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds

mm/sparse: refine usemap_size() a little

The current implementation calculates usemap_size in two steps:
    * calculate number of bytes to cover these bits
    * calculate number of "unsigned long" to cover these bytes

It would be more clear by:
    * calculate number of "unsigned long" to cover these bits
    * multiple it with sizeof(unsigned long)

This patch refine usemap_size() a little to make it more easy to
understand.

Link: http://lkml.kernel.org/r/20170310043713.96871-1-richard.weiyang@gmail.comSigned-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 82251963
...@@ -248,10 +248,7 @@ static int __meminit sparse_init_one_section(struct mem_section *ms, ...@@ -248,10 +248,7 @@ static int __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long usemap_size(void) unsigned long usemap_size(void)
{ {
unsigned long size_bytes; return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
size_bytes = roundup(size_bytes, sizeof(unsigned long));
return size_bytes;
} }
#ifdef CONFIG_MEMORY_HOTPLUG #ifdef CONFIG_MEMORY_HOTPLUG
......
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