blk-mq: use sparser tag layout for lower queue depth

[linux-2.6-block.git] / block / blk-mq-tag.h

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 06d4a2f0f7a04f10c218238d4620040f8a4f513a..7aa9f06654898e8f0b1e7ffdc96ef907aeb6fa4f 100644 (file)
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -11,8 +11,8 @@ struct bt_wait_state {
        wait_queue_head_t wait;
 } ____cacheline_aligned_in_smp;
 
-#define TAG_TO_INDEX(tag)      ((tag) / BITS_PER_LONG)
-#define TAG_TO_BIT(tag)                ((tag) & (BITS_PER_LONG - 1))
+#define TAG_TO_INDEX(bt, tag)  ((tag) >> (bt)->bits_per_word)
+#define TAG_TO_BIT(bt, tag)    ((tag) & ((1 << (bt)->bits_per_word) - 1))
 
 struct blk_mq_bitmap {
        unsigned long word;
@@ -22,9 +22,10 @@ struct blk_mq_bitmap {
 struct blk_mq_bitmap_tags {
        unsigned int depth;
        unsigned int wake_cnt;
+       unsigned int bits_per_word;
 
-       struct blk_mq_bitmap *map;
        unsigned int map_nr;
+       struct blk_mq_bitmap *map;
 
        unsigned int wake_index;
        struct bt_wait_state *bs;