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authorFernando Luis Vázquez Cao <fernando@oss.ntt.co.jp>2008-10-27 18:44:46 +0900
committerJens Axboe <jens.axboe@oracle.com>2008-12-29 08:28:41 +0100
commit88e740f1654bf28565edd528a060695c1f2b5ad7 (patch)
treec66a57396c9b881df1734f5b46e6681bc536c132
parent3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff)
block: add queue flag for paravirt frontend drivers
As is the case with SSD devices, we do not want to idle in AS/CFQ when the block device is a paravirt front-end driver. This patch adds a flag (QUEUE_FLAG_VIRT) which should be used by front-end drivers such as virtio_blk and xen-blkfront to indicate a paravirtualized device. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--include/linux/blkdev.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 031a315c0509..482e9600f7a2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -449,6 +449,7 @@ struct request_queue
#define QUEUE_FLAG_FAIL_IO 12 /* fake timeout */
#define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */
#define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */
+#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
static inline int queue_is_locked(struct request_queue *q)
{