Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: [PATCH 4/4] blk-mq: mark ctx as pending at batch in flush plug path | Date | Thu, 15 Oct 2015 11:26:43 -0400 |
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Ming Lei <ming.lei@canonical.com> writes:
> Most of times, flush plug should be the hottest I/O path, > so mark ctx as pending after all requests in the list are > inserted.
Hi, Ming,
Did you see some performance gain from this?
-Jeff
> > Signed-off-by: Ming Lei <ming.lei@canonical.com> > --- > block/blk-mq.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index deb5f4c..1c943b9 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -993,18 +993,25 @@ void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) > } > EXPORT_SYMBOL(blk_mq_delay_queue); > > -static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, > - struct request *rq, bool at_head) > +static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, > + struct blk_mq_ctx *ctx, > + struct request *rq, > + bool at_head) > { > - struct blk_mq_ctx *ctx = rq->mq_ctx; > - > trace_block_rq_insert(hctx->queue, rq); > > if (at_head) > list_add(&rq->queuelist, &ctx->rq_list); > else > list_add_tail(&rq->queuelist, &ctx->rq_list); > +} > + > +static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, > + struct request *rq, bool at_head) > +{ > + struct blk_mq_ctx *ctx = rq->mq_ctx; > > + __blk_mq_insert_req_list(hctx, ctx, rq, at_head); > blk_mq_hctx_mark_pending(hctx, ctx); > } > > @@ -1060,8 +1067,9 @@ static void blk_mq_insert_requests(struct request_queue *q, > rq = list_first_entry(list, struct request, queuelist); > list_del_init(&rq->queuelist); > rq->mq_ctx = ctx; > - __blk_mq_insert_request(hctx, rq, false); > + __blk_mq_insert_req_list(hctx, ctx, rq, false); > } > + blk_mq_hctx_mark_pending(hctx, ctx); > spin_unlock(&ctx->lock); > > blk_mq_run_hw_queue(hctx, from_schedule);
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