The patch titled Subject: mm/sparse: refine usemap_size() a little has been added to the -mm tree. Its filename is mm-sparse-refine-usemap_size-a-little.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-sparse-refine-usemap_size-a-little.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-sparse-refine-usemap_size-a-little.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Wei Yang <richard.weiyang@xxxxxxxxx> Subject: mm/sparse: refine usemap_size() a little 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@xxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/sparse.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff -puN mm/sparse.c~mm-sparse-refine-usemap_size-a-little mm/sparse.c --- a/mm/sparse.c~mm-sparse-refine-usemap_size-a-little +++ a/mm/sparse.c @@ -248,10 +248,7 @@ static int __meminit sparse_init_one_sec unsigned long usemap_size(void) { - unsigned long size_bytes; - size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8; - size_bytes = roundup(size_bytes, sizeof(unsigned long)); - return size_bytes; + return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); } #ifdef CONFIG_MEMORY_HOTPLUG _ Patches currently in -mm which might be from richard.weiyang@xxxxxxxxx are mm-sparse-refine-usemap_size-a-little.patch mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html