Ming Lei
2021-Feb-07 09:20 UTC
[PATCH V8 02/13] sbitmap: maintain allocation round_robin in sbitmap
Now allocation round_robin info is maintained by sbitmap_queue.
Actually, bit allocation belongs to sbitmap. Also the following
patch will move alloc_hint to sbitmap for users with high depth.
So move round_robin to sbitmap.
Cc: Omar Sandoval <osandov at fb.com>
Cc: Kashyap Desai <kashyap.desai at broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta at broadcom.com>
Cc: Ewan D. Milne <emilne at redhat.com>
Cc: Hannes Reinecke <hare at suse.de>
Cc: virtualization at lists.linux-foundation.org
Reviewed-by: Hannes Reinecke <hare at suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta at broadcom.com>
Signed-off-by: Ming Lei <ming.lei at redhat.com>
---
block/blk-mq.c | 2 +-
block/kyber-iosched.c | 3 ++-
drivers/vhost/scsi.c | 4 ++--
include/linux/sbitmap.h | 20 ++++++++++----------
lib/sbitmap.c | 28 ++++++++++++++--------------
5 files changed, 29 insertions(+), 28 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f21d922ecfaf..a2bac31afaff 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2729,7 +2729,7 @@ 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))
+ gfp, node, false))
goto free_ctxs;
hctx->nr_ctx = 0;
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index c25c41d0d061..d017c43c0041 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -479,7 +479,8 @@ 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)) {
+ ilog2(8), GFP_KERNEL, hctx->numa_node,
+ false)) {
while (--i >= 0)
sbitmap_free(&khd->kcq_map[i]);
goto err_kcqs;
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 4ce9f00ae10e..ab230f6f79e8 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -614,7 +614,7 @@ vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct
vhost_scsi_tpg *tpg,
return ERR_PTR(-EIO);
}
- tag = sbitmap_get(&svq->scsi_tags, 0, false);
+ tag = sbitmap_get(&svq->scsi_tags, 0);
if (tag < 0) {
pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
return ERR_PTR(-ENOMEM);
@@ -1512,7 +1512,7 @@ static int vhost_scsi_setup_vq_cmds(struct vhost_virtqueue
*vq, int max_cmds)
return 0;
if (sbitmap_init_node(&svq->scsi_tags, max_cmds, -1, GFP_KERNEL,
- NUMA_NO_NODE))
+ NUMA_NO_NODE, false))
return -ENOMEM;
svq->max_cmds = max_cmds;
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
index 16353fbee765..734ee6214cd6 100644
--- a/include/linux/sbitmap.h
+++ b/include/linux/sbitmap.h
@@ -56,6 +56,11 @@ struct sbitmap {
*/
unsigned int map_nr;
+ /**
+ * @round_robin: Allocate bits in strict round-robin order.
+ */
+ bool round_robin;
+
/**
* @map: Allocated bitmap.
*/
@@ -124,11 +129,6 @@ struct sbitmap_queue {
*/
atomic_t ws_active;
- /**
- * @round_robin: Allocate bits in strict round-robin order.
- */
- bool round_robin;
-
/**
* @min_shallow_depth: The minimum shallow depth which may be passed to
* sbitmap_queue_get_shallow() or __sbitmap_queue_get_shallow().
@@ -144,11 +144,14 @@ struct sbitmap_queue {
* given, a good default is chosen.
* @flags: Allocation flags.
* @node: Memory node to allocate on.
+ * @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).
*
* 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);
+ gfp_t flags, int node, bool round_robin);
/**
* sbitmap_free() - Free memory used by a &struct sbitmap.
@@ -174,15 +177,12 @@ 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.
- * @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).
*
* 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, bool round_robin);
+int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint);
/**
* sbitmap_get_shallow() - Try to allocate a free bit from a &struct
sbitmap,
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index d693d9213ceb..7000636933b3 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -33,7 +33,7 @@ static inline bool sbitmap_deferred_clear(struct sbitmap_word
*map)
}
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)
{
unsigned int bits_per_word;
unsigned int i;
@@ -58,6 +58,7 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth,
int shift,
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;
@@ -129,14 +130,14 @@ static int __sbitmap_get_word(unsigned long *word,
unsigned long depth,
}
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))
@@ -146,7 +147,7 @@ static int sbitmap_find_bit_in_index(struct sbitmap *sb, int
index,
return nr;
}
-int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin)
+int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
{
unsigned int i, index;
int nr = -1;
@@ -158,14 +159,13 @@ int sbitmap_get(struct sbitmap *sb, unsigned int
alloc_hint, bool round_robin)
* 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;
@@ -350,7 +350,8 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq,
unsigned int depth,
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);
if (ret)
return ret;
@@ -382,7 +383,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq,
unsigned int depth,
atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch);
}
- sbq->round_robin = round_robin;
return 0;
}
EXPORT_SYMBOL_GPL(sbitmap_queue_init_node);
@@ -424,12 +424,12 @@ int __sbitmap_queue_get(struct sbitmap_queue *sbq)
hint = depth ? prandom_u32() % depth : 0;
this_cpu_write(*sbq->alloc_hint, hint);
}
- nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin);
+ nr = sbitmap_get(&sbq->sb, hint);
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)) {
+ } else if (nr == hint || unlikely(sbq->sb.round_robin)) {
/* Only update the hint if we used it. */
hint = nr + 1;
if (hint >= depth - 1)
@@ -460,7 +460,7 @@ int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq,
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)) {
+ } else if (nr == hint || unlikely(sbq->sb.round_robin)) {
/* Only update the hint if we used it. */
hint = nr + 1;
if (hint >= depth - 1)
@@ -576,7 +576,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned
int nr,
smp_mb__after_atomic();
sbitmap_queue_wake_up(sbq);
- if (likely(!sbq->round_robin && nr < sbq->sb.depth))
+ if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth))
*per_cpu_ptr(sbq->alloc_hint, cpu) = nr;
}
EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
@@ -633,7 +633,7 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct
seq_file *m)
}
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);
--
2.29.2