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-rw-r--r--lib/sbitmap.c94
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;
}