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| author | Fernando Luis Vázquez Cao <fernando@oss.ntt.co.jp> | 2008-10-27 18:44:46 +0900 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-12-29 08:28:41 +0100 |
| commit | 88e740f1654bf28565edd528a060695c1f2b5ad7 (patch) | |
| tree | c66a57396c9b881df1734f5b46e6681bc536c132 | |
| parent | 3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff) | |
| download | blackbird-op-linux-88e740f1654bf28565edd528a060695c1f2b5ad7.tar.gz blackbird-op-linux-88e740f1654bf28565edd528a060695c1f2b5ad7.zip | |
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.h | 1 |
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) { |
