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From: Chaitanya Kulkarni <chaitanyak@nvidia.com>
To: Michael Marod <michael@michaelmarod.com>
Cc: Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: NVME performance regression in Linux 5.x due to lack of block level IO queueing
Date: Fri, 1 Apr 2022 02:59:00 +0000	[thread overview]
Message-ID: <a00e3a0d-8dff-c845-ed3b-9dc435187ecd@nvidia.com> (raw)
In-Reply-To: <YkZi+co1HchfRafa@kbusch-mbp.dhcp.thefacebook.com>


> Thanks for the info. I don't know of anything block or nvme specific that might
> explain an order of magnitude perf difference.
> 
> Could you try the same test without the filesytems? You mentioned using mdraid,
> so try '--filename=/dev/mdX'. If that also shows similiar performance
> difference, try using one of your nvme member drives directly, like
> '--filename=/dev/nvme1n1'. That should isolate which subsystem is contributing
> to the difference.
> 

With Keith's suggestions you can always take the perf numbers and
compare before and after mainly for nvme_queue_rq() and nvme_irq().

-ck



      reply	other threads:[~2022-04-01  2:59 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-30 14:32 Michael Marod
2022-03-30 14:50 ` Michael Marod
2022-03-31  0:11   ` Michael Marod
2022-03-31  4:35     ` Christoph Hellwig
2022-03-31 23:22       ` Michael Marod
2022-04-01  2:27         ` Keith Busch
2022-04-01  2:59           ` Chaitanya Kulkarni [this message]

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