Re: [PATCH 1/1] mmc: Set optimal I/O size when mmc_setip_queue

Ulf Hansson
2023-08-24T10:56:05Z

On Fri, 18 Aug 2023 at 04:45, <Sharp.Xia@mediatek.com> wrote:
>
> From: Sharp Xia <Sharp.Xia@mediatek.com>
>
> MMC does not set readahead and uses the default VM_READAHEAD_PAGES
> resulting in slower reading speed.
> Use the max_req_size reported by host driver to set the optimal
> I/O size to improve performance.

This seems reasonable to me. However, it would be nice if you could
share some performance numbers too - comparing before and after
$subject patch.

Kind regards
Uffe

>
> Signed-off-by: Sharp Xia <Sharp.Xia@mediatek.com>
> ---
> drivers/mmc/core/queue.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
> index b396e3900717..fc83c4917360 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -359,6 +359,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
> blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
> blk_queue_max_hw_sectors(mq->queue,
> min(host->max_blk_count, host->max_req_size / 512));
> + blk_queue_io_opt(mq->queue, host->max_req_size);
> if (host->can_dma_map_merge)
> WARN(!blk_queue_can_use_dma_map_merging(mq->queue,
> mmc_dev(host)),
> --
> 2.18.0
>