| Message ID | 20231203193307.542794-2-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bitops: add atomic find_bit() operations | expand |
On Sun 03-12-23 11:32:35, Yury Norov wrote: > __sbitmap_get_word() opencodes either find_and_set_bit_wrap(), or > find_and_set_next_bit() depending on hint and wrap parameters. > > Switch it to use the atomic find_bit() API. While here, simplify > sbitmap_find_bit_in_word(), which calls it. > > Signed-off-by: Yury Norov <yury.norov@gmail.com> Looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > lib/sbitmap.c | 46 ++++++++-------------------------------------- > 1 file changed, 8 insertions(+), 38 deletions(-) > > diff --git a/lib/sbitmap.c b/lib/sbitmap.c > index d0a5081dfd12..b21aebd07fd6 100644 > --- a/lib/sbitmap.c > +++ b/lib/sbitmap.c > @@ -133,38 +133,11 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth) > } > EXPORT_SYMBOL_GPL(sbitmap_resize); > > -static int __sbitmap_get_word(unsigned long *word, unsigned long depth, > +static inline int __sbitmap_get_word(unsigned long *word, unsigned long depth, > unsigned int hint, bool wrap) > { > - int nr; > - > - /* don't wrap if starting from 0 */ > - wrap = wrap && hint; > - > - while (1) { > - nr = find_next_zero_bit(word, depth, hint); > - if (unlikely(nr >= depth)) { > - /* > - * We started with an offset, and we didn't reset the > - * offset to 0 in a failure case, so start from 0 to > - * exhaust the map. > - */ > - if (hint && wrap) { > - hint = 0; > - continue; > - } > - return -1; > - } > - > - if (!test_and_set_bit_lock(nr, word)) > - break; > - > - hint = nr + 1; > - if (hint >= depth - 1) > - hint = 0; > - } > - > - return nr; > + return wrap ? find_and_set_bit_wrap_lock(word, depth, hint) : > + find_and_set_next_bit_lock(word, depth, hint); > } > > static int sbitmap_find_bit_in_word(struct sbitmap_word *map, > @@ -175,15 +148,12 @@ static int sbitmap_find_bit_in_word(struct sbitmap_word *map, > int nr; > > do { > - nr = __sbitmap_get_word(&map->word, depth, > - alloc_hint, wrap); > - if (nr != -1) > - break; > - if (!sbitmap_deferred_clear(map)) > - break; > - } while (1); > + nr = __sbitmap_get_word(&map->word, depth, alloc_hint, wrap); > + if (nr < depth) > + return nr; > + } while (sbitmap_deferred_clear(map)); > > - return nr; > + return -1; > } > > static int sbitmap_find_bit(struct sbitmap *sb, > -- > 2.40.1 >
On 12/3/23 12:32 PM, Yury Norov wrote: > diff --git a/lib/sbitmap.c b/lib/sbitmap.c > index d0a5081dfd12..b21aebd07fd6 100644 > --- a/lib/sbitmap.c > +++ b/lib/sbitmap.c > @@ -133,38 +133,11 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth) > } > EXPORT_SYMBOL_GPL(sbitmap_resize); > > -static int __sbitmap_get_word(unsigned long *word, unsigned long depth, > +static inline int __sbitmap_get_word(unsigned long *word, unsigned long depth, > unsigned int hint, bool wrap) > { > - int nr; > - > - /* don't wrap if starting from 0 */ > - wrap = wrap && hint; > - > - while (1) { > - nr = find_next_zero_bit(word, depth, hint); > - if (unlikely(nr >= depth)) { > - /* > - * We started with an offset, and we didn't reset the > - * offset to 0 in a failure case, so start from 0 to > - * exhaust the map. > - */ > - if (hint && wrap) { > - hint = 0; > - continue; > - } > - return -1; > - } > - > - if (!test_and_set_bit_lock(nr, word)) > - break; > - > - hint = nr + 1; > - if (hint >= depth - 1) > - hint = 0; > - } > - > - return nr; > + return wrap ? find_and_set_bit_wrap_lock(word, depth, hint) : > + find_and_set_next_bit_lock(word, depth, hint); > } Please make this: if (wrap) return find_and_set_bit_wrap_lock(word, depth, hint) : return find_and_set_next_bit_lock(word, depth, hint); so this is a lot more readable.
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index d0a5081dfd12..b21aebd07fd6 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -133,38 +133,11 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth) } EXPORT_SYMBOL_GPL(sbitmap_resize); -static int __sbitmap_get_word(unsigned long *word, unsigned long depth, +static inline int __sbitmap_get_word(unsigned long *word, unsigned long depth, unsigned int hint, bool wrap) { - int nr; - - /* don't wrap if starting from 0 */ - wrap = wrap && hint; - - while (1) { - nr = find_next_zero_bit(word, depth, hint); - if (unlikely(nr >= depth)) { - /* - * We started with an offset, and we didn't reset the - * offset to 0 in a failure case, so start from 0 to - * exhaust the map. - */ - if (hint && wrap) { - hint = 0; - continue; - } - return -1; - } - - if (!test_and_set_bit_lock(nr, word)) - break; - - hint = nr + 1; - if (hint >= depth - 1) - hint = 0; - } - - return nr; + return wrap ? find_and_set_bit_wrap_lock(word, depth, hint) : + find_and_set_next_bit_lock(word, depth, hint); } static int sbitmap_find_bit_in_word(struct sbitmap_word *map, @@ -175,15 +148,12 @@ static int sbitmap_find_bit_in_word(struct sbitmap_word *map, int nr; do { - nr = __sbitmap_get_word(&map->word, depth, - alloc_hint, wrap); - if (nr != -1) - break; - if (!sbitmap_deferred_clear(map)) - break; - } while (1); + nr = __sbitmap_get_word(&map->word, depth, alloc_hint, wrap); + if (nr < depth) + return nr; + } while (sbitmap_deferred_clear(map)); - return nr; + return -1; } static int sbitmap_find_bit(struct sbitmap *sb,
__sbitmap_get_word() opencodes either find_and_set_bit_wrap(), or find_and_set_next_bit() depending on hint and wrap parameters. Switch it to use the atomic find_bit() API. While here, simplify sbitmap_find_bit_in_word(), which calls it. Signed-off-by: Yury Norov <yury.norov@gmail.com> --- lib/sbitmap.c | 46 ++++++++-------------------------------------- 1 file changed, 8 insertions(+), 38 deletions(-)