From: "hch@infradead.org" <hch@infradead.org>
To: Stephen Bates <stephen.bates@microsemi.com>
Cc: "hch@infradead.org" <hch@infradead.org>,
"axboe@fb.com" <axboe@fb.com>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"keith.busch@intel.com" <keith.busch@intel.com>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Jon Derrick <jonathan.derrick@intel.com>
Subject: Re: [PATCH 0/2] Block: Give option to force io polling
Date: Thu, 12 May 2016 00:08:05 -0700 [thread overview]
Message-ID: <20160512070805.GE20802@infradead.org> (raw)
In-Reply-To: <D87A37E7A4AA544D853031D9A919C70B16901010@avsrvexchmbx2.microsemi.net>
On Mon, May 09, 2016 at 02:53:30PM +0000, Stephen Bates wrote:
> Christoph, this is a DRAM based NVMe device, the code for polling in NVMe was merged in 4.5 right? We are using the inbox NVMe driver. Here is some performance data:
>
> QD=1, single thread, random 4KB reads
>
> Polling Off: 12us Avg / 40us 99.99% ;
> Polling On: 9.5us Avg / 25us 99.99%
>
> Both the average and 99.99% reduction are of interest.
How does CPU usage look for common workloads with polling force
enabled? If it's really an overall win we should just add a quirk
to the NVMe driver to always force polling for this device based on the
PCI ID.
next prev parent reply other threads:[~2016-05-12 7:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-31 20:19 [PATCH 0/2] Block: Give option to force io polling Jon Derrick
2016-04-05 12:38 ` Christoph Hellwig
2016-04-05 15:54 ` Keith Busch
2016-04-05 17:27 ` Christoph Hellwig
2016-04-05 18:07 ` Stephen Bates
2016-05-05 19:44 ` Stephen Bates
2016-05-08 9:02 ` hch
2016-05-09 14:53 ` Stephen Bates
2016-05-12 7:08 ` hch [this message]
2016-05-12 17:27 ` Stephen Bates
2016-05-12 17:34 ` Derrick, Jonathan
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