ext4: use memweight()
authorAkinobu Mita <akinobu.mita@gmail.com>
Mon, 30 Jul 2012 21:41:08 +0000 (14:41 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Jul 2012 00:25:16 +0000 (17:25 -0700)
commit6017b485caeae5915956190b4f3d8307021e785d
treed2f3acfc4b8ea70db019367c3561ee272343a643
parent10d470849a7c6dd360e8ad4770160ad7af9adb4b
ext4: use memweight()

Convert ext4_count_free() to use memweight() instead of table lookup
based counting clear bits implementation.  This change only affects the
code segments enabled by EXT4FS_DEBUG.

Note that this memweight() call can't be replaced with a single
bitmap_weight() call, although the pointer to the memory area is aligned
to long-word boundary.  Because the size of the memory area may not be a
multiple of BITS_PER_LONG, then it returns wrong value on big-endian
architecture.

This also includes the following change.

- Remove unnecessary map == NULL check in ext4_count_free() which
  always takes non-null pointer as the memory area.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ext4/bitmap.c