block: reorder request_queue to remove 64 bit alignment padding

Reorder request_queue to remove 16 bytes of alignment padding in 64 bit
builds.

On my config this shrinks the size of this structure from 1608 to 1592
bytes and therefore needs one fewer cachelines.

Also trivially move the open bracket { to be on the same line as the
structure name to make it easier to grep.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6dcea6885a5d..c0cd9a2f22ef 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -260,8 +260,7 @@ struct queue_limits {
         unsigned char           discard_zeroes_data;
 };
 
-struct request_queue
-{
+struct request_queue {
         /*
          * Together with queue_head for cacheline sharing
          */
@@ -304,14 +303,14 @@ struct request_queue
         void                    *queuedata;
 
         /*
-         * queue needs bounce pages for pages above this limit
+         * various queue flags, see QUEUE_* below
          */
-        gfp_t                   bounce_gfp;
+        unsigned long           queue_flags;
 
         /*
-         * various queue flags, see QUEUE_* below
+         * queue needs bounce pages for pages above this limit
          */
-        unsigned long           queue_flags;
+        gfp_t                   bounce_gfp;
 
         /*
          * protects queue structures from reentrancy. ->__queue_lock should
@@ -334,8 +333,8 @@ struct request_queue
         unsigned int            nr_congestion_off;
         unsigned int            nr_batching;
 
-        void                    *dma_drain_buffer;
         unsigned int            dma_drain_size;
+        void                    *dma_drain_buffer;
         unsigned int            dma_pad_mask;
         unsigned int            dma_alignment;