| Message ID | 20170403232228.11208-4-bart.vanassche@sandisk.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Apr 03, 2017 at 04:22:26PM -0700, Bart Van Assche wrote: > If a tag set is shared among multiple hardware queues, leave > it to the block driver to rerun hardware queues. Hence remove > QUEUE_FLAG_RESTART and introduce blk_mq_ops.restart_hctx. > Remove blk_mq_sched_mark_restart_queue() because this > function has no callers. This looks fine, but I think it needs to also actually implement at least a dummy restart_hctx method for SCSI and NVMe to keep the existing functionality.
On Mon, Apr 03, 2017 at 04:22:26PM -0700, Bart Van Assche wrote: > If a tag set is shared among multiple hardware queues, leave > it to the block driver to rerun hardware queues. Hence remove > QUEUE_FLAG_RESTART and introduce blk_mq_ops.restart_hctx. > Remove blk_mq_sched_mark_restart_queue() because this > function has no callers. Hi, Bart, Kyber uses blk_mq_sched_mark_restart_queue() and the QUEUE_FLAG_RESTART bit. If it's not too much trouble, it'd make things easier for me if you left it in place. If it's a pain, it's fine if you get rid of it, I can reintroduce it in my series.
On Wed, 2017-04-05 at 13:41 -0700, Omar Sandoval wrote: > On Mon, Apr 03, 2017 at 04:22:26PM -0700, Bart Van Assche wrote: > > If a tag set is shared among multiple hardware queues, leave > > it to the block driver to rerun hardware queues. Hence remove > > QUEUE_FLAG_RESTART and introduce blk_mq_ops.restart_hctx. > > Remove blk_mq_sched_mark_restart_queue() because this > > function has no callers. > > Kyber uses blk_mq_sched_mark_restart_queue() and the QUEUE_FLAG_RESTART > bit. If it's not too much trouble, it'd make things easier for me if you > left it in place. If it's a pain, it's fine if you get rid of it, I can > reintroduce it in my series. Hello Omar, Would it be OK for you to reintroduce blk_mq_sched_mark_restart_queue()? Since that function does not yet have any users I can't test any changes I make to that function ... Thanks, Bart.
On Wed, Apr 05, 2017 at 08:51:51PM +0000, Bart Van Assche wrote: > On Wed, 2017-04-05 at 13:41 -0700, Omar Sandoval wrote: > > On Mon, Apr 03, 2017 at 04:22:26PM -0700, Bart Van Assche wrote: > > > If a tag set is shared among multiple hardware queues, leave > > > it to the block driver to rerun hardware queues. Hence remove > > > QUEUE_FLAG_RESTART and introduce blk_mq_ops.restart_hctx. > > > Remove blk_mq_sched_mark_restart_queue() because this > > > function has no callers. > > > > Kyber uses blk_mq_sched_mark_restart_queue() and the QUEUE_FLAG_RESTART > > bit. If it's not too much trouble, it'd make things easier for me if you > > left it in place. If it's a pain, it's fine if you get rid of it, I can > > reintroduce it in my series. > > Hello Omar, > > Would it be OK for you to reintroduce blk_mq_sched_mark_restart_queue()? > Since that function does not yet have any users I can't test any changes > I make to that function ... > > Thanks, > > Bart. Yeah, that's fine.
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 414ed4b3d266..f0c691a3ef9e 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -328,18 +328,11 @@ EXPORT_SYMBOL(blk_mq_sched_restart_hctx); void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx) { struct request_queue *q = hctx->queue; - unsigned int i; - - if (test_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) { - if (test_and_clear_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) { - queue_for_each_hw_ctx(q, hctx, i) - if (test_bit(BLK_MQ_S_SCHED_RESTART, - &hctx->state)) - blk_mq_sched_restart_hctx(hctx); - } - } else if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { + + if (q->mq_ops->restart_hctx) + q->mq_ops->restart_hctx(q, hctx); + else if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) blk_mq_sched_restart_hctx(hctx); - } } /* diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index a75b16b123f7..fe62b1eccf4c 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -131,20 +131,6 @@ static inline void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); } -/* - * Mark a hardware queue and the request queue it belongs to as needing a - * restart. - */ -static inline void blk_mq_sched_mark_restart_queue(struct blk_mq_hw_ctx *hctx) -{ - struct request_queue *q = hctx->queue; - - if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) - set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); - if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) - set_bit(QUEUE_FLAG_RESTART, &q->queue_flags); -} - static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx) { return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index f62f3ce2dc65..ebeea36ff9cd 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -86,6 +86,7 @@ struct blk_mq_queue_data { }; typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *); +typedef void (restart_fn)(struct request_queue *q, struct blk_mq_hw_ctx *hctx); typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool); typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int); @@ -109,6 +110,12 @@ struct blk_mq_ops { queue_rq_fn *queue_rq; /* + * Called upon request completion to rerun all hctxs that share a tag + * set with the hctx for which a request finished. + */ + restart_fn *restart_hctx; + + /* * Called on request timeout */ timeout_fn *timeout; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a2dc6b390d48..a80543ec8be7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -615,7 +615,6 @@ struct request_queue { #define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */ #define QUEUE_FLAG_DAX 26 /* device supports DAX */ #define QUEUE_FLAG_STATS 27 /* track rq completion times */ -#define QUEUE_FLAG_RESTART 28 /* queue needs restart at completion */ #define QUEUE_FLAG_POLL_STATS 29 /* collecting stats for hybrid polling */ #define QUEUE_FLAG_REGISTERED 30 /* queue has been registered to a disk */
If a tag set is shared among multiple hardware queues, leave it to the block driver to rerun hardware queues. Hence remove QUEUE_FLAG_RESTART and introduce blk_mq_ops.restart_hctx. Remove blk_mq_sched_mark_restart_queue() because this function has no callers. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> --- block/blk-mq-sched.c | 15 ++++----------- block/blk-mq-sched.h | 14 -------------- include/linux/blk-mq.h | 7 +++++++ include/linux/blkdev.h | 1 - 4 files changed, 11 insertions(+), 26 deletions(-)