| Message ID | 1527057202-2802-2-git-send-email-jianchao.w.wang@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 23, 2018 at 02:33:21PM +0800, Jianchao Wang wrote: > From: Jens Axboe <axboe@kernel.dk> > > No functional changes in this patch, just a prep patch for utilizing > this in an IO scheduler. Reviewed-by: Omar Sandoval <osandov@fb.com> > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > block/blk-mq-sched.c | 34 ++++++++++++++++++++++++---------- > include/linux/blk-mq.h | 3 ++- > 2 files changed, 26 insertions(+), 11 deletions(-) > > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index 25c14c5..b0f2c2a 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -268,19 +268,16 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, > EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); > > /* > - * Reverse check our software queue for entries that we could potentially > - * merge with. Currently includes a hand-wavy stop count of 8, to not spend > - * too much time checking for merges. > + * Iterate list of requests and see if we can merge this bio with any > + * of them. > */ > -static bool blk_mq_attempt_merge(struct request_queue *q, > - struct blk_mq_ctx *ctx, struct bio *bio) > +bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, > + struct bio *bio) > { > struct request *rq; > int checked = 8; > > - lockdep_assert_held(&ctx->lock); > - > - list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { > + list_for_each_entry_reverse(rq, list, queuelist) { > bool merged = false; > > if (!checked--) > @@ -305,13 +302,30 @@ static bool blk_mq_attempt_merge(struct request_queue *q, > continue; > } > > - if (merged) > - ctx->rq_merged++; > return merged; > } > > return false; > } > +EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge); > + > +/* > + * Reverse check our software queue for entries that we could potentially > + * merge with. Currently includes a hand-wavy stop count of 8, to not spend > + * too much time checking for merges. > + */ > +static bool blk_mq_attempt_merge(struct request_queue *q, > + struct blk_mq_ctx *ctx, struct bio *bio) > +{ > + lockdep_assert_held(&ctx->lock); > + > + if (blk_mq_bio_list_merge(q, &ctx->rq_list, bio)) { > + ctx->rq_merged++; > + return true; > + } > + > + return false; > +} > > bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) > { > diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h > index ebc34a5..fb35517 100644 > --- a/include/linux/blk-mq.h > +++ b/include/linux/blk-mq.h > @@ -259,7 +259,8 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, > void blk_mq_kick_requeue_list(struct request_queue *q); > void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); > void blk_mq_complete_request(struct request *rq); > - > +bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, > + struct bio *bio); > bool blk_mq_queue_stopped(struct request_queue *q); > void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); > void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); > -- > 2.7.4 >
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 25c14c5..b0f2c2a 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -268,19 +268,16 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); /* - * Reverse check our software queue for entries that we could potentially - * merge with. Currently includes a hand-wavy stop count of 8, to not spend - * too much time checking for merges. + * Iterate list of requests and see if we can merge this bio with any + * of them. */ -static bool blk_mq_attempt_merge(struct request_queue *q, - struct blk_mq_ctx *ctx, struct bio *bio) +bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, + struct bio *bio) { struct request *rq; int checked = 8; - lockdep_assert_held(&ctx->lock); - - list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { + list_for_each_entry_reverse(rq, list, queuelist) { bool merged = false; if (!checked--) @@ -305,13 +302,30 @@ static bool blk_mq_attempt_merge(struct request_queue *q, continue; } - if (merged) - ctx->rq_merged++; return merged; } return false; } +EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge); + +/* + * Reverse check our software queue for entries that we could potentially + * merge with. Currently includes a hand-wavy stop count of 8, to not spend + * too much time checking for merges. + */ +static bool blk_mq_attempt_merge(struct request_queue *q, + struct blk_mq_ctx *ctx, struct bio *bio) +{ + lockdep_assert_held(&ctx->lock); + + if (blk_mq_bio_list_merge(q, &ctx->rq_list, bio)) { + ctx->rq_merged++; + return true; + } + + return false; +} bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index ebc34a5..fb35517 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -259,7 +259,8 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, void blk_mq_kick_requeue_list(struct request_queue *q); void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); void blk_mq_complete_request(struct request *rq); - +bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, + struct bio *bio); bool blk_mq_queue_stopped(struct request_queue *q); void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);