From: Fernando Luis Vázquez Cao Date: Mon, 27 Oct 2008 09:44:46 +0000 (+0900) Subject: block: add queue flag for paravirt frontend drivers X-Git-Tag: firefly_0821_release~16469^2~42 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=88e740f1654bf28565edd528a060695c1f2b5ad7;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Jens Axboe --- 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) {