Messages in this thread Patch in this message | | | Date | Mon, 28 Mar 2011 18:15:47 -0400 | From | Mike Snitzer <> | Subject | [PATCH] block: eliminate ELEVATOR_INSERT_REQUEUE (was: Re: elevator private data for REQ_FLUSH) |
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On Mon, Mar 28 2011 at 4:23am -0400, Tejun Heo <tj@kernel.org> wrote:
> On Sat, Mar 26, 2011 at 12:21:56AM -0400, Mike Snitzer wrote: > > Should blk_kick_flush() process the flush request without calling > > elv_insert() -- like is done with open coded list_add() in > > blk_insert_flush()? > > > > Or should blk_insert_flush() use elv_insert() with > > ELEVATOR_INSERT_REQUEUE too? > > Hmmm... I would prefer the latter. Given that INSERT_REQUEUE and > FRONT are no longer different, it would probably be better to use > FRONT tho. The only reason REQUEUE is used there is to avoid kicking > the queue from elv_insert(), which is gone now.
OK, I came up with the following patch.
Jens, this is just a natural cleanup given the code that resulted from the flush-merge and onstack plugging changes coming together.
From: Mike Snitzer <snitzer@redhat.com> Subject: block: eliminate ELEVATOR_INSERT_REQUEUE
elv_insert() no longer has a need to differentiate between ELEVATOR_INSERT_REQUEUE and ELEVATOR_INSERT_FRONT. The onstack plugging changes eliminated the need to avoid unplugging the queue (via ELEVATOR_INSERT_REQUEUE).
Also, in blk_insert_flush(), use elv_insert() with ELEVATOR_INSERT_FRONT rather than open-coding the equivalent.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> --- block/blk-flush.c | 4 ++-- block/elevator.c | 3 +-- include/linux/elevator.h | 5 ++--- 3 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c index 93d5fd8..2c43044 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -261,7 +261,7 @@ static bool blk_kick_flush(struct request_queue *q) q->flush_rq.end_io = flush_end_io; q->flush_pending_idx ^= 1; - elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_REQUEUE); + elv_insert(q, &q->flush_rq, ELEVATOR_INSERT_FRONT); return true; } @@ -312,7 +312,7 @@ void blk_insert_flush(struct request *rq) */ if ((policy & REQ_FSEQ_DATA) && !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) { - list_add(&rq->queuelist, &q->queue_head); + elv_insert(q, rq, ELEVATOR_INSERT_FRONT); return; } diff --git a/block/elevator.c b/block/elevator.c index c387d31..df7c4ba 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -610,7 +610,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) rq->cmd_flags &= ~REQ_STARTED; - elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE); + elv_insert(q, rq, ELEVATOR_INSERT_FRONT); } void elv_drain_elevator(struct request_queue *q) @@ -662,7 +662,6 @@ void elv_insert(struct request_queue *q, struct request *rq, int where) rq->q = q; switch (where) { - case ELEVATOR_INSERT_REQUEUE: case ELEVATOR_INSERT_FRONT: rq->cmd_flags |= REQ_SOFTBARRIER; list_add(&rq->queuelist, &q->queue_head); diff --git a/include/linux/elevator.h b/include/linux/elevator.h index d93efcc445..0b4a354 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -164,9 +164,8 @@ extern struct request *elv_rb_find(struct rb_root *, sector_t); #define ELEVATOR_INSERT_FRONT 1 #define ELEVATOR_INSERT_BACK 2 #define ELEVATOR_INSERT_SORT 3 -#define ELEVATOR_INSERT_REQUEUE 4 -#define ELEVATOR_INSERT_FLUSH 5 -#define ELEVATOR_INSERT_SORT_MERGE 6 +#define ELEVATOR_INSERT_FLUSH 4 +#define ELEVATOR_INSERT_SORT_MERGE 5 /* * return values from elevator_may_queue_fn
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