sbitmap: push per-cpu last_tag into sbitmap_queue

[mirror_ubuntu-zesty-kernel.git] / block / blk-mq-tag.c

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 2cbdecd594e9704c6c807c0e30b6bc0ffe2fc196..c9a22dbbbda1e701b5ce18b938c48a0cfe463abe 100644 (file)
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -94,39 +94,21 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
 #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 @@ static int bt_get(struct blk_mq_alloc_data *data,
        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 @@ static int bt_get(struct blk_mq_alloc_data *data,
                 * 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 @@ static int bt_get(struct blk_mq_alloc_data *data,
                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 @@ static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data)
        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_tag(struct blk_mq_alloc_data *data)
 
 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 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
        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 @@ void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag,
                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);
        }
 }