sbitmap: push per-cpu last_tag into sbitmap_queue
Allocating your own per-cpu allocation hint separately makes for an
awkward API. Instead, allocate the per-cpu hint as part of the struct
sbitmap_queue. There's no point for a struct sbitmap_queue without the
cache, but you can still use a bare struct sbitmap.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 2cbdecd..c9a22db 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -94,39 +94,21 @@
#define BT_ALLOC_RR(tags) (tags->alloc_policy == BLK_TAG_ALLOC_RR)
static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt,
- unsigned int *tag_cache, struct blk_mq_tags *tags)
+ struct blk_mq_tags *tags)
{
- unsigned int last_tag;
- int tag;
-
if (!hctx_may_queue(hctx, bt))
return -1;
-
- last_tag = *tag_cache;
- tag = sbitmap_get(&bt->sb, last_tag, BT_ALLOC_RR(tags));
-
- if (tag == -1) {
- *tag_cache = 0;
- } else if (tag == last_tag || unlikely(BT_ALLOC_RR(tags))) {
- last_tag = tag + 1;
- if (last_tag >= bt->sb.depth - 1)
- last_tag = 0;
- *tag_cache = last_tag;
- }
-
- return tag;
+ return __sbitmap_queue_get(bt, BT_ALLOC_RR(tags));
}
-static int bt_get(struct blk_mq_alloc_data *data,
- struct sbitmap_queue *bt,
- struct blk_mq_hw_ctx *hctx,
- unsigned int *last_tag, struct blk_mq_tags *tags)
+static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt,
+ struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags)
{
struct sbq_wait_state *ws;
DEFINE_WAIT(wait);
int tag;
- tag = __bt_get(hctx, bt, last_tag, tags);
+ tag = __bt_get(hctx, bt, tags);
if (tag != -1)
return tag;
@@ -137,7 +119,7 @@
do {
prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
- tag = __bt_get(hctx, bt, last_tag, tags);
+ tag = __bt_get(hctx, bt, tags);
if (tag != -1)
break;
@@ -154,7 +136,7 @@
* Retry tag allocation after running the hardware queue,
* as running the queue may also have found completions.
*/
- tag = __bt_get(hctx, bt, last_tag, tags);
+ tag = __bt_get(hctx, bt, tags);
if (tag != -1)
break;
@@ -168,7 +150,6 @@
if (data->flags & BLK_MQ_REQ_RESERVED) {
bt = &data->hctx->tags->breserved_tags;
} else {
- last_tag = &data->ctx->last_tag;
hctx = data->hctx;
bt = &hctx->tags->bitmap_tags;
}
@@ -185,7 +166,7 @@
int tag;
tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx,
- &data->ctx->last_tag, data->hctx->tags);
+ data->hctx->tags);
if (tag >= 0)
return tag + data->hctx->tags->nr_reserved_tags;
@@ -194,15 +175,15 @@
static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data)
{
- int tag, zero = 0;
+ int tag;
if (unlikely(!data->hctx->tags->nr_reserved_tags)) {
WARN_ON_ONCE(1);
return BLK_MQ_TAG_FAIL;
}
- tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, &zero,
- data->hctx->tags);
+ tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL,
+ data->hctx->tags);
if (tag < 0)
return BLK_MQ_TAG_FAIL;
@@ -216,8 +197,8 @@
return __blk_mq_get_tag(data);
}
-void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag,
- unsigned int *last_tag)
+void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ unsigned int tag)
{
struct blk_mq_tags *tags = hctx->tags;
@@ -225,12 +206,12 @@
const int real_tag = tag - tags->nr_reserved_tags;
BUG_ON(real_tag >= tags->nr_tags);
- sbitmap_queue_clear(&tags->bitmap_tags, real_tag);
- if (likely(tags->alloc_policy == BLK_TAG_ALLOC_FIFO))
- *last_tag = real_tag;
+ sbitmap_queue_clear(&tags->bitmap_tags, real_tag,
+ BT_ALLOC_RR(tags), ctx->cpu);
} else {
BUG_ON(tag >= tags->nr_reserved_tags);
- sbitmap_queue_clear(&tags->breserved_tags, tag);
+ sbitmap_queue_clear(&tags->breserved_tags, tag,
+ BT_ALLOC_RR(tags), ctx->cpu);
}
}