]> www.infradead.org Git - users/jedix/linux-maple.git/commit
mm/util: reduce stack usage of folio_mapcount
authorKairui Song <kasong@tencent.com>
Mon, 1 Aug 2022 17:31:55 +0000 (01:31 +0800)
committerAndrew Morton <akpm@linux-foundation.org>
Mon, 22 Aug 2022 22:58:00 +0000 (15:58 -0700)
commit5c54950f5a5b86c6418802cf4af6934f803cbf6d
tree561a05bc8988657b8d417c5819301b81002be7cb
parentdbad879ef6f41b60a20b7714459097533e400b7a
mm/util: reduce stack usage of folio_mapcount

folio_test_hugetlb() will call PageHeadHuge which is a function call,
and blocks the compiler from recognizing this redundant load.

After rearranging the code, stack usage is dropped from 32 to 24, and
the function size is smaller (tested on GCC 12):

Before:
Stack usage:
mm/util.c:845:5:folio_mapcount  32      static
Size:
0000000000000ea0 00000000000000c7 T folio_mapcount

After:
Stack usage:
mm/util.c:845:5:folio_mapcount  24      static
Size:
0000000000000ea0 00000000000000b0 T folio_mapcount

Link: https://lkml.kernel.org/r/20220801173155.92008-1-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/util.c