On 18/07/19 03:04, Wei Yang wrote:
> The value left in nr is the number of bits for the last word, which
> could be calculate the last word mask directly.
>
> Remove the unnecessary size.
Hi,
the value left in nr is _not_ the number of bits for the last word if
the start and the end are in the same word. For example, if start %
BITS_PER_LONG was 3 and nr == 1, you'd have:
- before the patch BITMAP_LAST_WORD_MASK(4)
- after the patch BITMAP_LAST_WORD_MASK(1)
Paolo
> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
>
> ---
> v2: refine bitmap_set_atomic too, suggested from Peter
> ---
> util/bitmap.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/util/bitmap.c b/util/bitmap.c
> index 1753ff7f5b..5b15249796 100644
> --- a/util/bitmap.c
> +++ b/util/bitmap.c
> @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned
> long *bitmap1,
> void bitmap_set(unsigned long *map, long start, long nr)
> {
> unsigned long *p = map + BIT_WORD(start);
> - const long size = start + nr;
> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
>
> @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr)
> p++;
> }
> if (nr) {
> - mask_to_set &= BITMAP_LAST_WORD_MASK(size);
> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
> *p |= mask_to_set;
> }
> }
> @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr)
> void bitmap_set_atomic(unsigned long *map, long start, long nr)
> {
> unsigned long *p = map + BIT_WORD(start);
> - const long size = start + nr;
> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
>
> @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start,
> long nr)
>
> /* Last word */
> if (nr) {
> - mask_to_set &= BITMAP_LAST_WORD_MASK(size);
> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
> atomic_or(p, mask_to_set);
> } else {
> /* If we avoided the full barrier in atomic_or(), issue a
> @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start,
> long nr)
> void bitmap_clear(unsigned long *map, long start, long nr)
> {
> unsigned long *p = map + BIT_WORD(start);
> - const long size = start + nr;
> int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
> unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
>
> @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr)
> p++;
> }
> if (nr) {
> - mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
> + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr);
> *p &= ~mask_to_clear;
> }
> }
>
