Commit 88e740f1 authored by Fernando Luis Vázquez Cao's avatar Fernando Luis Vázquez Cao Committed by Jens Axboe

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: default avatarFernando Luis Vazquez Cao <>
Signed-off-by: default avatarJens Axboe <>
parent 3c92ec8a
......@@ -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)
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