diff options
| -rw-r--r-- | lib/sbitmap.c | 94 |
1 files changed, 51 insertions, 43 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 2261136ae067..5b3e56d68dab 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -20,6 +20,47 @@ #include <linux/sbitmap.h> #include <linux/seq_file.h> +/* + * See if we have deferred clears that we can batch move + */ +static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index) +{ + unsigned long mask, val; + unsigned long __maybe_unused flags; + bool ret = false; + + /* Silence bogus lockdep warning */ +#if defined(CONFIG_LOCKDEP) + local_irq_save(flags); +#endif + spin_lock(&sb->map[index].swap_lock); + + if (!sb->map[index].cleared) + goto out_unlock; + + /* + * First get a stable cleared mask, setting the old mask to 0. + */ + do { + mask = sb->map[index].cleared; + } while (cmpxchg(&sb->map[index].cleared, mask, 0) != mask); + + /* + * Now clear the masked bits in our free word + */ + do { + val = sb->map[index].word; + } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val); + + ret = true; +out_unlock: + spin_unlock(&sb->map[index].swap_lock); +#if defined(CONFIG_LOCKDEP) + local_irq_restore(flags); +#endif + return ret; +} + int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, gfp_t flags, int node) { @@ -70,6 +111,9 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth) unsigned int bits_per_word = 1U << sb->shift; unsigned int i; + for (i = 0; i < sb->map_nr; i++) + sbitmap_deferred_clear(sb, i); + sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); @@ -112,47 +156,6 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth, return nr; } -/* - * See if we have deferred clears that we can batch move - */ -static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index) -{ - unsigned long mask, val; - unsigned long __maybe_unused flags; - bool ret = false; - - /* Silence bogus lockdep warning */ -#if defined(CONFIG_LOCKDEP) - local_irq_save(flags); -#endif - spin_lock(&sb->map[index].swap_lock); - - if (!sb->map[index].cleared) - goto out_unlock; - - /* - * First get a stable cleared mask, setting the old mask to 0. - */ - do { - mask = sb->map[index].cleared; - } while (cmpxchg(&sb->map[index].cleared, mask, 0) != mask); - - /* - * Now clear the masked bits in our free word - */ - do { - val = sb->map[index].word; - } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val); - - ret = true; -out_unlock: - spin_unlock(&sb->map[index].swap_lock); -#if defined(CONFIG_LOCKDEP) - local_irq_restore(flags); -#endif - return ret; -} - static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, unsigned int alloc_hint, bool round_robin) { @@ -215,6 +218,7 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, index = SB_NR_TO_INDEX(sb, alloc_hint); for (i = 0; i < sb->map_nr; i++) { +again: nr = __sbitmap_get_word(&sb->map[index].word, min(sb->map[index].depth, shallow_depth), SB_NR_TO_BIT(sb, alloc_hint), true); @@ -223,6 +227,9 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, break; } + if (sbitmap_deferred_clear(sb, index)) + goto again; + /* Jump to next index. */ index++; alloc_hint = index << sb->shift; @@ -242,7 +249,7 @@ bool sbitmap_any_bit_set(const struct sbitmap *sb) unsigned int i; for (i = 0; i < sb->map_nr; i++) { - if (sb->map[i].word) + if (sb->map[i].word & ~sb->map[i].cleared) return true; } return false; @@ -255,9 +262,10 @@ bool sbitmap_any_bit_clear(const struct sbitmap *sb) for (i = 0; i < sb->map_nr; i++) { const struct sbitmap_word *word = &sb->map[i]; + unsigned long mask = word->word & ~word->cleared; unsigned long ret; - ret = find_first_zero_bit(&word->word, word->depth); + ret = find_first_zero_bit(&mask, word->depth); if (ret < word->depth) return true; } |