From: Bart Van Assche <bvanassche@acm.org>
To: Chengming Zhou <chengming.zhou@linux.dev>,
axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com,
kbusch@kernel.org
Cc: mst@redhat.com, sagi@grimberg.me,
damien.lemoal@opensource.wdc.com, kch@nvidia.com,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
zhouchengming@bytedance.com
Subject: Re: [PATCH 0/6] blk-mq: optimize the queue_rqs() support
Date: Sat, 26 Aug 2023 17:45:53 -0700 [thread overview]
Message-ID: <c48a294c-a8a9-63ae-182f-e1d757f6179e@acm.org> (raw)
In-Reply-To: <84c857f7-9966-6125-92c4-1b2fa96fb98d@linux.dev>
On 8/25/23 01:24, Chengming Zhou wrote:
> I don't know the details of the UFS devices bad performance problem.
> But I feel it maybe caused by the too lazy queue idle handling, which
> is now only handled in queue timeout work.
Hi Chengming,
The root cause of the UFS performance problem is the fair sharing
algorithm itself: reducing the active queue count only happens after
the request queue timeout has expired. This is way too slow. Last time
it was proposed to remove that algorithm Yu Kuai promised to replace it
by a better algorithm. Since progress on the replacement algorithm has
stalled I'm asking again whether everyone agrees to remove the fairness
algorithm.
Thanks,
Bart.
next prev parent reply other threads:[~2023-08-27 0:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-24 14:43 [PATCH 0/6] blk-mq: optimize the queue_rqs() support chengming.zhou
2023-08-24 14:43 ` [PATCH 1/6] blk-mq: account active requests when get driver tag chengming.zhou
2023-08-24 14:43 ` [PATCH 2/6] blk-mq: remove RQF_MQ_INFLIGHT chengming.zhou
2023-08-24 14:44 ` [PATCH 3/6] blk-mq: support batched queue_rqs() on shared tags queue chengming.zhou
2023-08-24 14:44 ` [PATCH 4/6] blk-mq: update driver tags request table when start request chengming.zhou
2023-08-24 14:44 ` [PATCH 5/6] blk-mq: fix potential reorder of request state and deadline chengming.zhou
2023-08-24 14:44 ` [PATCH 6/6] block/null_blk: add queue_rqs() support chengming.zhou
2023-08-24 17:02 ` [PATCH 0/6] blk-mq: optimize the " Bart Van Assche
2023-08-25 8:24 ` Chengming Zhou
2023-08-27 0:45 ` Bart Van Assche [this message]
2023-09-02 15:00 ` Chengming Zhou
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