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From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Hannes Reinecke <hare@suse.de>, Ming Lei <ming.lei@redhat.com>,
	Yu Kuai <yukuai3@huawei.com>
Subject: Re: [PATCH v2] block: Improve IOPS by removing the fairness code
Date: Tue, 26 Mar 2024 07:22:29 +0100	[thread overview]
Message-ID: <20240326062229.GA7554@lst.de> (raw)
In-Reply-To: <20240325221420.1468801-1-bvanassche@acm.org>

On Mon, Mar 25, 2024 at 03:14:19PM -0700, Bart Van Assche wrote:
> On my test setup (x86 VM with 72 CPU cores) this patch results in 2.9% more
> IOPS. IOPS have been measured as follows:
> 
> $ modprobe null_blk nr_devices=1 completion_nsec=0
> $ fio --bs=4096 --disable_clat=1 --disable_slat=1 --group_reporting=1 \
>       --gtod_reduce=1 --invalidate=1 --ioengine=psync --ioscheduler=none \
>       --norandommap --runtime=60 --rw=randread --thread --time_based=1 \
>       --buffered=0 --numjobs=64 --name=/dev/nullb0 --filename=/dev/nullb0

And how does it behave when you have multiple request_queues sharing
a tag_set with very unevent use that could cause one to starve all
the tags?  Because that is what this code exists for.


  reply	other threads:[~2024-03-26  6:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-25 22:14 [PATCH v2] block: Improve IOPS by removing the fairness code Bart Van Assche
2024-03-26  6:22 ` Christoph Hellwig [this message]
2024-03-26 17:36   ` Bart Van Assche
2024-03-28  4:58     ` Christoph Hellwig

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