Messages in this thread Patch in this message | | | Subject | [PATCH 1/3] block: add queue flag for paravirt frontend drivers | From | Fernando Luis Vázquez Cao <> | Date | Mon, 27 Oct 2008 18:44:46 +0900 |
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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> ---
diff -urNp linux-2.6.28-rc2-orig/include/linux/blkdev.h linux-2.6.28-rc2/include/linux/blkdev.h --- linux-2.6.28-rc2-orig/include/linux/blkdev.h 2008-10-27 17:41:58.000000000 +0900 +++ linux-2.6.28-rc2/include/linux/blkdev.h 2008-10-27 17:34:49.000000000 +0900 @@ -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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