> Il giorno 6 ago 2021, alle ore 04:08, Yu Kuai <yukuai3@xxxxxxxxxx> ha scritto:
>
> If bfq keep
keeps
> dispatching requests with same size, the following
> information are
is stored
> stored if CONFIG_BFQ_GROUP_IOSCHED is enabled:
>
> 1) the size
> 2) the count of requests
> 3) when the first request was dispatched
>
> These will be used in later patch to support concurrent sync
> io in such situation.
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> block/bfq-iosched.c | 15 +++++++++++++++
> block/bfq-iosched.h | 16 ++++++++++++++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index a780205a1be4..7df3fc0ef4ef 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -4936,6 +4936,20 @@ static bool bfq_has_work(struct blk_mq_hw_ctx *hctx)
> bfq_tot_busy_queues(bfqd) > 0;
> }
>
> +static void bfq_update_dispatch_size_info(struct bfq_data *bfqd,
> + unsigned int size)
> +{
> +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> + if (bfqd->dispatch_size == size) {
> + bfqd->dispatch_count++;
> + } else {
> + bfqd->dispatch_size = size;
> + bfqd->dispatch_count = 1;
> + bfqd->dispatch_time = jiffies;
> + }
> +#endif
> +}
> +
> static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx)
> {
> struct bfq_data *bfqd = hctx->queue->elevator->elevator_data;
> @@ -5019,6 +5033,7 @@ static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx)
> bfqd->rq_in_driver++;
> start_rq:
> rq->rq_flags |= RQF_STARTED;
> + bfq_update_dispatch_size_info(bfqd, blk_rq_bytes(rq));
> }
> exit:
> return rq;
> diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
> index 610769214f72..9ab498839e7c 100644
> --- a/block/bfq-iosched.h
> +++ b/block/bfq-iosched.h
> @@ -777,6 +777,22 @@ struct bfq_data {
> * function)
> */
> unsigned int word_depths[2][2];
> +
> +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> + /* the size of last dispatched request */
> + unsigned int dispatch_size;
> + /*
> + * If bfq keep dispatching requests with same size, this store the
keeps ... stores
> + * count of requests. We use unsigned long here, so we don't care
> + * about overflow.
> + */
> + unsigned long dispatch_count;
> + /*
> + * If bfq keep dispatching requests with same size, this store the
keeps ... stores
Thanks,
Paolo
> + * time when the first request was dispatched.
> + */
> + unsigned long dispatch_time;
> +#endif
> };
>
> enum bfqq_state_flags {
> --
> 2.31.1
>
