From: Ming Lei <ming.lei@redhat.com>
To: Lin Feng <linf@wangsu.com>
Cc: axboe@kernel.dk, paolo.valente@linaro.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 2/2] bfq/mq-deadline: remove redundant check for passthrough request
Date: Fri, 16 Apr 2021 10:14:48 +0800 [thread overview]
Message-ID: <YHjzGPO+SoHMEghy@T590> (raw)
In-Reply-To: <20210415034326.214227-1-linf@wangsu.com>
On Thu, Apr 15, 2021 at 11:43:26AM +0800, Lin Feng wrote:
> Since commit 01e99aeca39796003 'blk-mq: insert passthrough request into
> hctx->dispatch directly', passthrough request should not appear in
> IO-scheduler any more, so blk_rq_is_passthrough checking in addon IO
> schedulers is redundant.
>
> (Notes: this patch passes generic IO load test with hdds under SAS
> controller and hdds under AHCI controller but obviously not covers all.
> Not sure if passthrough request can still escape into IO scheduler from
> blk_mq_sched_insert_requests, which is used by blk_mq_flush_plug_list and
> has lots of indirect callers.)
>
> Signed-off-by: Lin Feng <linf@wangsu.com>
> ---
> block/bfq-iosched.c | 2 +-
> block/mq-deadline.c | 7 ++-----
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 95586137194e..b827c9212b02 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -5627,7 +5627,7 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
>
> spin_lock_irq(&bfqd->lock);
> bfqq = bfq_init_rq(rq);
> - if (!bfqq || at_head || blk_rq_is_passthrough(rq)) {
> + if (!bfqq || at_head) {
> if (at_head)
> list_add(&rq->queuelist, &bfqd->dispatch);
> else
> diff --git a/block/mq-deadline.c b/block/mq-deadline.c
> index f3631a287466..04aded71ead2 100644
> --- a/block/mq-deadline.c
> +++ b/block/mq-deadline.c
> @@ -500,11 +500,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
>
> trace_block_rq_insert(rq);
>
> - if (at_head || blk_rq_is_passthrough(rq)) {
> - if (at_head)
> - list_add(&rq->queuelist, &dd->dispatch);
> - else
> - list_add_tail(&rq->queuelist, &dd->dispatch);
> + if (at_head) {
> + list_add(&rq->queuelist, &dd->dispatch);
> } else {
> deadline_add_rq_rb(dd, rq);
>
> --
> 2.30.2
>
Looks fine:
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Thanks,
Ming
next prev parent reply other threads:[~2021-04-16 2:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-15 3:43 [RFC PATCH 2/2] bfq/mq-deadline: remove redundant check for passthrough request Lin Feng
2021-04-16 2:14 ` Ming Lei [this message]
2021-04-16 12:09 ` Jens Axboe
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