2011-05-04 08:21:41

by Shaohua Li

Subject: [patch v2 1/3] block: add a non-queueable flush flag

flush request isn't queueable in some drives. Add a flag to let driver
notify block layer about this. We can optimize flush performance with the
knowledge.

Signed-off-by: Shaohua Li <[email protected]>
---
include/linux/blkdev.h | 11 +++++++++++
1 file changed, 11 insertions(+)

Index: linux/include/linux/blkdev.h
===================================================================
--- linux.orig/include/linux/blkdev.h 2011-05-04 14:23:42.000000000 +0800
+++ linux/include/linux/blkdev.h 2011-05-04 14:24:40.000000000 +0800
@@ -364,6 +364,7 @@ struct request_queue
* for flush operations
*/
unsigned int flush_flags;
+ unsigned int flush_not_queueable:1;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
unsigned long flush_pending_since;
@@ -549,6 +550,16 @@ static inline void blk_clear_queue_full(
queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
}

+static inline void blk_set_queue_flush_queueable(struct request_queue *q,
+ bool queueable)
+{
+ q->flush_not_queueable = !queueable;
+}
+
+static inline bool blk_queue_flush_queueable(struct request_queue *q)
+{
+ return !q->flush_not_queueable;
+}

/*
* mergeable request must not have _NOMERGE or _BARRIER bit set, nor may

2011-05-04 09:05:16

by Tejun Heo

Subject: Re: [patch v2 1/3] block: add a non-queueable flush flag

Hello,

On Wed, May 04, 2011 at 04:17:26PM +0800, [email protected] wrote:
> flush request isn't queueable in some drives. Add a flag to let driver
> notify block layer about this. We can optimize flush performance with the
> knowledge.
>
> Signed-off-by: Shaohua Li <[email protected]>
> ---
> include/linux/blkdev.h | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> Index: linux/include/linux/blkdev.h
> ===================================================================
> --- linux.orig/include/linux/blkdev.h 2011-05-04 14:23:42.000000000 +0800
> +++ linux/include/linux/blkdev.h 2011-05-04 14:24:40.000000000 +0800
> @@ -364,6 +364,7 @@ struct request_queue
> * for flush operations
> */
> unsigned int flush_flags;
> + unsigned int flush_not_queueable:1;
> unsigned int flush_pending_idx:1;
> unsigned int flush_running_idx:1;
> unsigned long flush_pending_since;
> @@ -549,6 +550,16 @@ static inline void blk_clear_queue_full(
> queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
> }
>
> +static inline void blk_set_queue_flush_queueable(struct request_queue *q,
> + bool queueable)
> +{
> + q->flush_not_queueable = !queueable;
> +}
> +
> +static inline bool blk_queue_flush_queueable(struct request_queue *q)
> +{
> + return !q->flush_not_queueable;
> +}

In the block layer, these setters live in block/blk-settings.c and
usually don't have _set in their names.

Also, negation in the interface is slightly bothering but I can't
think of better name meaning !queueable either, so unless someone can
come up with better name, it should do, I think.

Thank you.

--
tejun