From: Jens Axboe <axboe@kernel.dk>
To: Bart Van Assche <bvanassche@acm.org>, linux-block@vger.kernel.org
Subject: Re: [PATCH 2/2] block/mq-deadline: fallback to per-cpu insertion buckets under contention
Date: Thu, 18 Jan 2024 11:33:28 -0700 [thread overview]
Message-ID: <c9f1b580-2241-4415-aa48-e4b7e1bacdea@kernel.dk> (raw)
In-Reply-To: <0ca63d05-fc5b-4e6a-a828-52eb24305545@acm.org>
On 1/18/24 11:31 AM, Bart Van Assche wrote:
> On 1/18/24 10:04, Jens Axboe wrote:
>> If we attempt to insert a list of requests but someone else is already
>> running an insertion, then fallback to queueing it internally and let
>> the existing inserter finish the operation.
>
> Because this patch adds significant complexity: what are the use cases
> that benefit from this kind of optimization? Are these perhaps workloads
> on systems with many CPU cores and fast storage? If the storage is fast,
> why to use mq-deadline instead of "none" as I/O-scheduler?
You and others complain that mq-deadline is slow and doesn't scale,
these two patches help improve that situation. Not sure why this is even
a question?
--
Jens Axboe
next prev parent reply other threads:[~2024-01-18 18:33 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-18 18:04 [PATCHSET RFC 0/2] mq-deadline scalability improvements Jens Axboe
2024-01-18 18:04 ` [PATCH 1/2] block/mq-deadline: serialize request dispatching Jens Axboe
2024-01-18 18:24 ` Bart Van Assche
2024-01-18 18:45 ` Jens Axboe
2024-01-18 18:51 ` Bart Van Assche
2024-01-18 18:55 ` Jens Axboe
2024-01-19 2:40 ` Ming Lei
2024-01-19 15:49 ` Jens Axboe
2024-01-18 18:04 ` [PATCH 2/2] block/mq-deadline: fallback to per-cpu insertion buckets under contention Jens Axboe
2024-01-18 18:25 ` Keith Busch
2024-01-18 18:28 ` Jens Axboe
2024-01-18 18:31 ` Bart Van Assche
2024-01-18 18:33 ` Jens Axboe [this message]
2024-01-18 18:53 ` Bart Van Assche
2024-01-18 18:56 ` Jens Axboe
2024-01-18 20:46 ` Bart Van Assche
2024-01-18 20:52 ` Jens Axboe
2024-01-19 23:11 ` Bart Van Assche
2024-01-18 19:29 ` [PATCHSET RFC 0/2] mq-deadline scalability improvements Jens Axboe
2024-01-18 20:22 ` Jens Axboe
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