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Date: Fri, 4 Aug 2017 08:07:47 +0200
From: Johannes Thumshirn <jthumshirn@suse.de>
Subject: Re: [PATCH 5/5] libnvdimm: add DMA support for pmem blk-mq
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To: Dan Williams <dan.j.williams@intel.com>
Cc: "Koul, Vinod" <vinod.koul@intel.com>, "dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>, "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>
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On Thu, Aug 03, 2017 at 09:15:12AM -0700, Dan Williams wrote:
> > I can put in a tunable knob like Johannes suggested and leave the
> > default for that to what it is currently. And we can adjust as necessary
> > as we do more testing.
> =

> That's the problem, we need a multi-dimensional knob. It's not just
> transfer-size that effects total delivered bandwidth.

If Dan opposes it so much, I'm OK with no tunable. I'm just expressing my
concern that we get reports like this [1] one here as a result.

Thanks,
	Johannes

[1] http://marc.info/?l=3Dlinux-kernel&m=3D150175029403913&w=3D2

-- =

Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=FCrnberg
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