Ming Lei <ming....@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.
>
> Signed-off-by: Ming Lei <ming....@canonical.com>
I agree this looks like a better approach. Whether it makes a
difference or not, I can't say.
Reviewed-by: Jeff Moyer <jmo...@redhat.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 a5e33bc..b169e2d 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -990,18 +990,25 @@ 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);
> }
>
> @@ -1057,8 +1064,9 @@ 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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