| Message ID | 22aa78389c9b4613841716c5b7bd89aa@hyperstone.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: Improve block layer requeueing behavior | expand |
On Wed, 26 Oct 2022 at 09:30, Christian Löhle <CLoehle@hyperstone.com> wrote: > > In case the driver set RQF_DONTPREP flag, requeue the request as head as > it is likely that the backing storage already had a request to an > adjacent region, so getting the requeued request out as soon as possible > may give us some performance benefit. This is a bit handwavy to me. Would you mind extending this with a small concrete example, to better understand the benefit? > > Signed-off-by: Christian Loehle <cloehle@hyperstone.com> Other than the above nitpick, I can't think of any obvious unwanted side-effects this could have. So, feel free to add: Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > block/blk-mq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 33292c01875d..d863c826fb23 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1429,7 +1429,7 @@ static void blk_mq_requeue_work(struct work_struct *work) > * merge. > */ > if (rq->rq_flags & RQF_DONTPREP) > - blk_mq_request_bypass_insert(rq, false, false); > + blk_mq_request_bypass_insert(rq, true, false); > else > blk_mq_sched_insert_request(rq, true, false, false); > } > -- > 2.37.3 > Hyperstone GmbH | Reichenaustr. 39a | 78467 Konstanz > Managing Director: Dr. Jan Peter Berns. > Commercial register of local courts: Freiburg HRB381782 >
Jens could you consider this patch? As far as I can see Barts series has not been merged in any form that would fix my problem and even if it does, requeuing RQF_DONTPREP as head seems on par at worst and a performance improvement at best. -----Original Message----- From: Christian Löhle Sent: Mittwoch, 26. Oktober 2022 09:29 To: axboe@kernel.dk; ulf.hansson@linaro.org; linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org; 'linux-block@vger.kernel.org' <linux-block@vger.kernel.org> Cc: 'Avri Altman' <Avri.Altman@wdc.com>; adrian.hunter@intel.com; vincent.whitchurch@axis.com; 'Christian Löhle' <CLoehle@hyperstone.com> Subject: [PATCH 1/3] block: Requeue req as head if driver touched it In case the driver set RQF_DONTPREP flag, requeue the request as head as it is likely that the backing storage already had a request to an adjacent region, so getting the requeued request out as soon as possible may give us some performance benefit. Signed-off-by: Christian Loehle <cloehle@hyperstone.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 33292c01875d..d863c826fb23 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1429,7 +1429,7 @@ static void blk_mq_requeue_work(struct work_struct *work) * merge. */ if (rq->rq_flags & RQF_DONTPREP) - blk_mq_request_bypass_insert(rq, false, false); + blk_mq_request_bypass_insert(rq, true, false); else blk_mq_sched_insert_request(rq, true, false, false); } -- 2.37.3 Hyperstone GmbH | Reichenaustr. 39a | 78467 Konstanz Managing Director: Dr. Jan Peter Berns. Commercial register of local courts: Freiburg HRB381782
diff --git a/block/blk-mq.c b/block/blk-mq.c index 33292c01875d..d863c826fb23 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1429,7 +1429,7 @@ static void blk_mq_requeue_work(struct work_struct *work) * merge. */ if (rq->rq_flags & RQF_DONTPREP) - blk_mq_request_bypass_insert(rq, false, false); + blk_mq_request_bypass_insert(rq, true, false); else blk_mq_sched_insert_request(rq, true, false, false); }
In case the driver set RQF_DONTPREP flag, requeue the request as head as it is likely that the backing storage already had a request to an adjacent region, so getting the requeued request out as soon as possible may give us some performance benefit. Signed-off-by: Christian Loehle <cloehle@hyperstone.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)