From: Paolo Valente <paolo.valente@linaro.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
ulf.hansson@linaro.org, linus.walleij@linaro.org,
broonie@kernel.org, bfq-iosched@googlegroups.com,
oleksandr@natalenko.name, mancha@tower-research.com,
Paolo Valente <paolo.valente@linaro.org>
Subject: [PATCH BUGFIX IMPROVEMENT 09/14] block, bfq: fix sequential rq detection in rate estimation
Date: Tue, 29 Jan 2019 12:06:33 +0100 [thread overview]
Message-ID: <20190129110638.12652-10-paolo.valente@linaro.org> (raw)
In-Reply-To: <20190129110638.12652-1-paolo.valente@linaro.org>
In bfq_update_peak_rate, to check whether an I/O request rq is
sequential, only the seek distance of rq w.r.t. the last request
dispatched is controlled. This is not sufficient for non-rotational
storage, where the size of rq is at least as relevant. This commit
adds the missing control.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
block/bfq-iosched.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index c1bb5e5fcdc4..12228af16198 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -235,6 +235,11 @@ static struct kmem_cache *bfq_pool;
#define BFQQ_SEEK_THR (sector_t)(8 * 100)
#define BFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
+#define BFQ_RQ_SEEKY(bfqd, last_pos, rq) \
+ (get_sdist(last_pos, rq) > \
+ BFQQ_SEEK_THR && \
+ (!blk_queue_nonrot(bfqd->queue) || \
+ blk_rq_sectors(rq) < BFQQ_SECT_THR_NONROT))
#define BFQQ_CLOSE_THR (sector_t)(8 * 1024)
#define BFQQ_SEEKY(bfqq) (hweight32(bfqq->seek_history) > 19)
@@ -2754,7 +2759,7 @@ static void bfq_update_peak_rate(struct bfq_data *bfqd, struct request *rq)
if ((bfqd->rq_in_driver > 0 ||
now_ns - bfqd->last_completion < BFQ_MIN_TT)
- && get_sdist(bfqd->last_position, rq) < BFQQ_SEEK_THR)
+ && !BFQ_RQ_SEEKY(bfqd, bfqd->last_position, rq))
bfqd->sequential_samples++;
bfqd->tot_sectors_dispatched += blk_rq_sectors(rq);
@@ -4511,10 +4516,7 @@ bfq_update_io_seektime(struct bfq_data *bfqd, struct bfq_queue *bfqq,
struct request *rq)
{
bfqq->seek_history <<= 1;
- bfqq->seek_history |=
- get_sdist(bfqq->last_request_pos, rq) > BFQQ_SEEK_THR &&
- (!blk_queue_nonrot(bfqd->queue) ||
- blk_rq_sectors(rq) < BFQQ_SECT_THR_NONROT);
+ bfqq->seek_history |= BFQ_RQ_SEEKY(bfqd, bfqq->last_request_pos, rq);
}
static void bfq_update_has_short_ttime(struct bfq_data *bfqd,
--
2.20.1
next prev parent reply other threads:[~2019-01-29 11:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 11:06 [PATCH BUGFIX IMPROVEMENT 00/14] batch of patches for next linux release Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 01/14] block, bfq: do not consider interactive queues in srt filtering Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 02/14] block, bfq: avoid selecting a queue w/o budget Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 03/14] block, bfq: make sure queue budgets are not below service received Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 04/14] block, bfq: remove case of redirected bic from insert_request Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 05/14] block, bfq: consider also ioprio classes in symmetry detection Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 06/14] block, bfq: split function bfq_better_to_idle Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 07/14] block, bfq: do not plug I/O of in-service queue when harmful Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 08/14] block, bfq: unconditionally plug I/O in asymmetric scenarios Paolo Valente
2019-01-29 11:06 ` Paolo Valente [this message]
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 10/14] block, bfq: fix queue removal from weights tree Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 11/14] block, bfq: reduce threshold for detecting command queueing Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 12/14] block, bfq: port commit "cfq-iosched: improve hw_tag detection" Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 13/14] block, bfq: do not overcharge writes in asymmetric scenarios Paolo Valente
2019-01-29 11:06 ` [PATCH BUGFIX IMPROVEMENT 14/14] block, bfq: fix in-service-queue check for queue merging Paolo Valente
2019-01-31 19:50 ` [PATCH BUGFIX IMPROVEMENT 00/14] batch of patches for next linux release Jens Axboe
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