[PATCH v2 14/14] ublk: cache-align struct ublk_io

[Caleb Sander Mateos <csander@purestorage.com>]

struct ublk_io is already 56 bytes on 64-bit architectures, so round it
up to a full cache line (typically 64 bytes). This ensures a single
ublk_io doesn't span multiple cache lines and prevents false sharing if
consecutive ublk_io's are accessed by different daemon tasks.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index ebc56681eb68..740141c63a93 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -186,11 +186,11 @@ struct ublk_io {
 	unsigned task_registered_buffers;
 
 	/* auto-registered buffer, valid if UBLK_IO_FLAG_AUTO_BUF_REG is set */
 	u16 buf_index;
 	void *buf_ctx_handle;
-};
+} ____cacheline_aligned_in_smp;
 
 struct ublk_queue {
 	int q_id;
 	int q_depth;
 
-- 
2.45.2