#include <linux/sbitmap.h>
#include <linux/seq_file.h>
+static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
+{
+ unsigned depth = sb->depth;
+
+ sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
+ if (!sb->alloc_hint)
+ return -ENOMEM;
+
+ if (depth && !sb->round_robin) {
+ int i;
+
+ for_each_possible_cpu(i)
+ *per_cpu_ptr(sb->alloc_hint, i) = prandom_u32() % depth;
+ }
+ return 0;
+}
+
+static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
+ unsigned int depth)
+{
+ unsigned hint;
+
+ hint = this_cpu_read(*sb->alloc_hint);
+ if (unlikely(hint >= depth)) {
+ hint = depth ? prandom_u32() % depth : 0;
+ this_cpu_write(*sb->alloc_hint, hint);
+ }
+
+ return hint;
+}
+
+static inline void update_alloc_hint_after_get(struct sbitmap *sb,
+ unsigned int depth,
+ unsigned int hint,
+ unsigned int nr)
+{
+ if (nr == -1) {
+ /* If the map is full, a hint won't do us much good. */
+ this_cpu_write(*sb->alloc_hint, 0);
+ } else if (nr == hint || unlikely(sb->round_robin)) {
+ /* Only update the hint if we used it. */
+ hint = nr + 1;
+ if (hint >= depth - 1)
+ hint = 0;
+ this_cpu_write(*sb->alloc_hint, hint);
+ }
+}
+
/*
* See if we have deferred clears that we can batch move
*/
}
int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
- gfp_t flags, int node)
+ gfp_t flags, int node, bool round_robin,
+ bool alloc_hint)
{
unsigned int bits_per_word;
unsigned int i;
- if (shift < 0) {
- shift = ilog2(BITS_PER_LONG);
- /*
- * If the bitmap is small, shrink the number of bits per word so
- * we spread over a few cachelines, at least. If less than 4
- * bits, just forget about it, it's not going to work optimally
- * anyway.
- */
- if (depth >= 4) {
- while ((4U << shift) > depth)
- shift--;
- }
- }
+ if (shift < 0)
+ shift = sbitmap_calculate_shift(depth);
+
bits_per_word = 1U << shift;
if (bits_per_word > BITS_PER_LONG)
return -EINVAL;
sb->shift = shift;
sb->depth = depth;
sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
+ sb->round_robin = round_robin;
if (depth == 0) {
sb->map = NULL;
return 0;
}
+ if (alloc_hint) {
+ if (init_alloc_hint(sb, flags))
+ return -ENOMEM;
+ } else {
+ sb->alloc_hint = NULL;
+ }
+
sb->map = kcalloc_node(sb->map_nr, sizeof(*sb->map), flags, node);
- if (!sb->map)
+ if (!sb->map) {
+ free_percpu(sb->alloc_hint);
return -ENOMEM;
+ }
for (i = 0; i < sb->map_nr; i++) {
sb->map[i].depth = min(depth, bits_per_word);
}
static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
- unsigned int alloc_hint, bool round_robin)
+ unsigned int alloc_hint)
{
struct sbitmap_word *map = &sb->map[index];
int nr;
do {
nr = __sbitmap_get_word(&map->word, map->depth, alloc_hint,
- !round_robin);
+ !sb->round_robin);
if (nr != -1)
break;
if (!sbitmap_deferred_clear(map))
return nr;
}
-int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin)
+static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
{
unsigned int i, index;
int nr = -1;
* alloc_hint to find the right word index. No point in looping
* twice in find_next_zero_bit() for that case.
*/
- if (round_robin)
+ if (sb->round_robin)
alloc_hint = SB_NR_TO_BIT(sb, alloc_hint);
else
alloc_hint = 0;
for (i = 0; i < sb->map_nr; i++) {
- nr = sbitmap_find_bit_in_index(sb, index, alloc_hint,
- round_robin);
+ nr = sbitmap_find_bit_in_index(sb, index, alloc_hint);
if (nr != -1) {
nr += index << sb->shift;
break;
return nr;
}
+
+int sbitmap_get(struct sbitmap *sb)
+{
+ int nr;
+ unsigned int hint, depth;
+
+ if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
+ return -1;
+
+ depth = READ_ONCE(sb->depth);
+ hint = update_alloc_hint_before_get(sb, depth);
+ nr = __sbitmap_get(sb, hint);
+ update_alloc_hint_after_get(sb, depth, hint, nr);
+
+ return nr;
+}
EXPORT_SYMBOL_GPL(sbitmap_get);
-int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint,
- unsigned long shallow_depth)
+static int __sbitmap_get_shallow(struct sbitmap *sb,
+ unsigned int alloc_hint,
+ unsigned long shallow_depth)
{
unsigned int i, index;
int nr = -1;
return nr;
}
+
+int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth)
+{
+ int nr;
+ unsigned int hint, depth;
+
+ if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
+ return -1;
+
+ depth = READ_ONCE(sb->depth);
+ hint = update_alloc_hint_before_get(sb, depth);
+ nr = __sbitmap_get_shallow(sb, hint, shallow_depth);
+ update_alloc_hint_after_get(sb, depth, hint, nr);
+
+ return nr;
+}
EXPORT_SYMBOL_GPL(sbitmap_get_shallow);
bool sbitmap_any_bit_set(const struct sbitmap *sb)
return weight;
}
-static unsigned int sbitmap_weight(const struct sbitmap *sb)
+static unsigned int sbitmap_cleared(const struct sbitmap *sb)
{
- return __sbitmap_weight(sb, true);
+ return __sbitmap_weight(sb, false);
}
-static unsigned int sbitmap_cleared(const struct sbitmap *sb)
+unsigned int sbitmap_weight(const struct sbitmap *sb)
{
- return __sbitmap_weight(sb, false);
+ return __sbitmap_weight(sb, true) - sbitmap_cleared(sb);
}
+EXPORT_SYMBOL_GPL(sbitmap_weight);
void sbitmap_show(struct sbitmap *sb, struct seq_file *m)
{
seq_printf(m, "depth=%u\n", sb->depth);
- seq_printf(m, "busy=%u\n", sbitmap_weight(sb) - sbitmap_cleared(sb));
+ seq_printf(m, "busy=%u\n", sbitmap_weight(sb));
seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb));
seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift);
seq_printf(m, "map_nr=%u\n", sb->map_nr);
int ret;
int i;
- ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node);
+ ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node,
+ round_robin, true);
if (ret)
return ret;
- sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
- if (!sbq->alloc_hint) {
- sbitmap_free(&sbq->sb);
- return -ENOMEM;
- }
-
- if (depth && !round_robin) {
- for_each_possible_cpu(i)
- *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth;
- }
-
sbq->min_shallow_depth = UINT_MAX;
sbq->wake_batch = sbq_calc_wake_batch(sbq, depth);
atomic_set(&sbq->wake_index, 0);
sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node);
if (!sbq->ws) {
- free_percpu(sbq->alloc_hint);
sbitmap_free(&sbq->sb);
return -ENOMEM;
}
atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch);
}
- sbq->round_robin = round_robin;
return 0;
}
EXPORT_SYMBOL_GPL(sbitmap_queue_init_node);
int __sbitmap_queue_get(struct sbitmap_queue *sbq)
{
- unsigned int hint, depth;
- int nr;
-
- hint = this_cpu_read(*sbq->alloc_hint);
- depth = READ_ONCE(sbq->sb.depth);
- if (unlikely(hint >= depth)) {
- hint = depth ? prandom_u32() % depth : 0;
- this_cpu_write(*sbq->alloc_hint, hint);
- }
- nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin);
-
- if (nr == -1) {
- /* If the map is full, a hint won't do us much good. */
- this_cpu_write(*sbq->alloc_hint, 0);
- } else if (nr == hint || unlikely(sbq->round_robin)) {
- /* Only update the hint if we used it. */
- hint = nr + 1;
- if (hint >= depth - 1)
- hint = 0;
- this_cpu_write(*sbq->alloc_hint, hint);
- }
-
- return nr;
+ return sbitmap_get(&sbq->sb);
}
EXPORT_SYMBOL_GPL(__sbitmap_queue_get);
int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq,
unsigned int shallow_depth)
{
- unsigned int hint, depth;
- int nr;
-
WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth);
- hint = this_cpu_read(*sbq->alloc_hint);
- depth = READ_ONCE(sbq->sb.depth);
- if (unlikely(hint >= depth)) {
- hint = depth ? prandom_u32() % depth : 0;
- this_cpu_write(*sbq->alloc_hint, hint);
- }
- nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth);
-
- if (nr == -1) {
- /* If the map is full, a hint won't do us much good. */
- this_cpu_write(*sbq->alloc_hint, 0);
- } else if (nr == hint || unlikely(sbq->round_robin)) {
- /* Only update the hint if we used it. */
- hint = nr + 1;
- if (hint >= depth - 1)
- hint = 0;
- this_cpu_write(*sbq->alloc_hint, hint);
- }
-
- return nr;
+ return sbitmap_get_shallow(&sbq->sb, shallow_depth);
}
EXPORT_SYMBOL_GPL(__sbitmap_queue_get_shallow);
smp_mb__after_atomic();
sbitmap_queue_wake_up(sbq);
- if (likely(!sbq->round_robin && nr < sbq->sb.depth))
- *per_cpu_ptr(sbq->alloc_hint, cpu) = nr;
+ if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth))
+ *per_cpu_ptr(sbq->sb.alloc_hint, cpu) = nr;
}
EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
if (!first)
seq_puts(m, ", ");
first = false;
- seq_printf(m, "%u", *per_cpu_ptr(sbq->alloc_hint, i));
+ seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i));
}
seq_puts(m, "}\n");
}
seq_puts(m, "}\n");
- seq_printf(m, "round_robin=%d\n", sbq->round_robin);
+ seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin);
seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth);
}
EXPORT_SYMBOL_GPL(sbitmap_queue_show);
projects / linux-2.6-microblaze.git / blobdiff