@@ -2688,7 +2688,7 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set,
goto free_cpumask;
if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8),
- gfp, node, false))
+ gfp, node, false, false))
goto free_ctxs;
hctx->nr_ctx = 0;
@@ -480,7 +480,7 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
for (i = 0; i < KYBER_NUM_DOMAINS; i++) {
if (sbitmap_init_node(&khd->kcq_map[i], hctx->nr_ctx,
ilog2(8), GFP_KERNEL, hctx->numa_node,
- false)) {
+ false, false)) {
while (--i >= 0)
sbitmap_free(&khd->kcq_map[i]);
goto err_kcqs;
@@ -70,6 +70,14 @@ struct sbitmap {
* @map: Allocated bitmap.
*/
struct sbitmap_word *map;
+
+ /*
+ * @alloc_hint: Cache of last successfully allocated or freed bit.
+ *
+ * This is per-cpu, which allows multiple users to stick to different
+ * cachelines until the map is exhausted.
+ */
+ unsigned int __percpu *alloc_hint;
};
#define SBQ_WAIT_QUEUES 8
@@ -105,14 +113,6 @@ struct sbitmap_queue {
*/
struct sbitmap sb;
- /*
- * @alloc_hint: Cache of last successfully allocated or freed bit.
- *
- * This is per-cpu, which allows multiple users to stick to different
- * cachelines until the map is exhausted.
- */
- unsigned int __percpu *alloc_hint;
-
/**
* @wake_batch: Number of bits which must be freed before we wake up any
* waiters.
@@ -152,11 +152,13 @@ struct sbitmap_queue {
* @round_robin: If true, be stricter about allocation order; always allocate
* starting from the last allocated bit. This is less efficient
* than the default behavior (false).
+ * @alloc_hint: If true, apply percpu hint for where to start searching for
+ * a free bit.
*
* Return: Zero on success or negative errno on failure.
*/
int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
- gfp_t flags, int node, bool round_robin);
+ gfp_t flags, int node, bool round_robin, bool alloc_hint);
/**
* sbitmap_free() - Free memory used by a &struct sbitmap.
@@ -164,6 +166,7 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
*/
static inline void sbitmap_free(struct sbitmap *sb)
{
+ free_percpu(sb->alloc_hint);
kfree(sb->map);
sb->map = NULL;
}
@@ -181,19 +184,17 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth);
/**
* sbitmap_get() - Try to allocate a free bit from a &struct sbitmap.
* @sb: Bitmap to allocate from.
- * @alloc_hint: Hint for where to start searching for a free bit.
*
* This operation provides acquire barrier semantics if it succeeds.
*
* Return: Non-negative allocated bit number if successful, -1 otherwise.
*/
-int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint);
+int sbitmap_get(struct sbitmap *sb);
/**
* sbitmap_get_shallow() - Try to allocate a free bit from a &struct sbitmap,
* limiting the depth used from each word.
* @sb: Bitmap to allocate from.
- * @alloc_hint: Hint for where to start searching for a free bit.
* @shallow_depth: The maximum number of bits to allocate from a single word.
*
* This rather specific operation allows for having multiple users with
@@ -205,8 +206,7 @@ int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint);
*
* Return: Non-negative allocated bit number if successful, -1 otherwise.
*/
-int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint,
- unsigned long shallow_depth);
+int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth);
/**
* sbitmap_any_bit_set() - Check for a set bit in a &struct sbitmap.
@@ -320,6 +320,18 @@ static inline void sbitmap_deferred_clear_bit(struct sbitmap *sb, unsigned int b
set_bit(SB_NR_TO_BIT(sb, bitnr), addr);
}
+/*
+ * Pair of sbitmap_get, and this one applies both cleared bit and
+ * allocation hint.
+ */
+static inline void sbitmap_put(struct sbitmap *sb, unsigned int bitnr)
+{
+ sbitmap_deferred_clear_bit(sb, bitnr);
+
+ if (likely(sb->alloc_hint && !sb->round_robin && bitnr < sb->depth))
+ *this_cpu_ptr(sb->alloc_hint) = bitnr;
+}
+
static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr)
{
return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
@@ -368,7 +380,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
static inline void sbitmap_queue_free(struct sbitmap_queue *sbq)
{
kfree(sbq->ws);
- free_percpu(sbq->alloc_hint);
sbitmap_free(&sbq->sb);
}
@@ -9,52 +9,51 @@
#include <linux/sbitmap.h>
#include <linux/seq_file.h>
-static int init_alloc_hint(struct sbitmap_queue *sbq, gfp_t flags)
+static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
{
- unsigned depth = sbq->sb.depth;
+ unsigned depth = sb->depth;
- sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
- if (!sbq->alloc_hint)
+ sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
+ if (!sb->alloc_hint)
return -ENOMEM;
- if (depth && !sbq->sb.round_robin) {
+ if (depth && !sb->round_robin) {
int i;
for_each_possible_cpu(i)
- *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth;
+ *per_cpu_ptr(sb->alloc_hint, i) = prandom_u32() % depth;
}
-
return 0;
}
-static inline unsigned update_alloc_hint_before_get(struct sbitmap_queue *sbq,
+static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
unsigned int depth)
{
unsigned hint;
- hint = this_cpu_read(*sbq->alloc_hint);
+ hint = this_cpu_read(*sb->alloc_hint);
if (unlikely(hint >= depth)) {
hint = depth ? prandom_u32() % depth : 0;
- this_cpu_write(*sbq->alloc_hint, hint);
+ this_cpu_write(*sb->alloc_hint, hint);
}
return hint;
}
-static inline void update_alloc_hint_after_get(struct sbitmap_queue *sbq,
+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(*sbq->alloc_hint, 0);
- } else if (nr == hint || unlikely(sbq->sb.round_robin)) {
+ 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(*sbq->alloc_hint, hint);
+ this_cpu_write(*sb->alloc_hint, hint);
}
}
@@ -91,7 +90,8 @@ static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index)
}
int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
- gfp_t flags, int node, bool round_robin)
+ gfp_t flags, int node, bool round_robin,
+ bool alloc_hint)
{
unsigned int bits_per_word;
unsigned int i;
@@ -123,9 +123,18 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
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);
@@ -204,7 +213,7 @@ static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
return nr;
}
-int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
+static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
{
unsigned int i, index;
int nr = -1;
@@ -236,10 +245,27 @@ int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
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;
@@ -271,6 +297,22 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint,
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)
@@ -408,15 +450,10 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
int i;
ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node,
- round_robin);
+ round_robin, true);
if (ret)
return ret;
- if (init_alloc_hint(sbq, flags) != 0) {
- sbitmap_free(&sbq->sb);
- return -ENOMEM;
- }
-
sbq->min_shallow_depth = UINT_MAX;
sbq->wake_batch = sbq_calc_wake_batch(sbq, depth);
atomic_set(&sbq->wake_index, 0);
@@ -424,7 +461,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
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;
}
@@ -466,32 +502,16 @@ EXPORT_SYMBOL_GPL(sbitmap_queue_resize);
int __sbitmap_queue_get(struct sbitmap_queue *sbq)
{
- unsigned int hint, depth;
- int nr;
-
- depth = READ_ONCE(sbq->sb.depth);
- hint = update_alloc_hint_before_get(sbq, depth);
- nr = sbitmap_get(&sbq->sb, hint);
- update_alloc_hint_after_get(sbq, depth, hint, nr);
-
- 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);
- depth = READ_ONCE(sbq->sb.depth);
- hint = update_alloc_hint_before_get(sbq, depth);
- nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth);
- update_alloc_hint_after_get(sbq, depth, hint, nr);
-
- return nr;
+ return sbitmap_get_shallow(&sbq->sb, shallow_depth);
}
EXPORT_SYMBOL_GPL(__sbitmap_queue_get_shallow);
@@ -600,7 +620,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
sbitmap_queue_wake_up(sbq);
if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth))
- *per_cpu_ptr(sbq->alloc_hint, cpu) = nr;
+ *per_cpu_ptr(sbq->sb.alloc_hint, cpu) = nr;
}
EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
@@ -638,7 +658,7 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m)
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");