diff options
| author | Akinobu Mita <akinobu.mita@gmail.com> | 2012-07-30 14:40:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 17:25:16 -0700 |
| commit | 639b9e34f15e4b2c30068a4e4485586af0cdf709 (patch) | |
| tree | a84e3277a55757dac4630e3d20bc353b195c3c10 /include/linux/string.h | |
| parent | f7f95056779eb69c5fc3ac30e5cb6fd28bdbba43 (diff) | |
string: introduce memweight()
memweight() is the function that counts the total number of bits set in
memory area. Unlike bitmap_weight(), memweight() takes pointer and size
in bytes to specify a memory area which does not need to be aligned to
long-word boundary.
[akpm@linux-foundation.org: rename `w' to `ret']
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Anders Larsen <al@alarsen.net>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/string.h')
| -rw-r--r-- | include/linux/string.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/string.h b/include/linux/string.h index e033564f10b..ffe0442e18d 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -145,4 +145,7 @@ static inline bool strstarts(const char *str, const char *prefix) return strncmp(str, prefix, strlen(prefix)) == 0; } #endif + +extern size_t memweight(const void *ptr, size_t bytes); + #endif /* _LINUX_STRING_H_ */ |