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Date: Fri, 24 Apr 2015 10:49:28 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
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        Geoffrey Gerfin <ggerfin@nvidia.com>,
        John McKenna <jmckenna@nvidia.com>, akpm@linux-foundation.org
Subject: Re: Interacting with coherent memory on external devices
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On Fri, 24 Apr 2015, Paul E. McKenney wrote:

> can deliver, but where the cost of full-fledge hand tuning cannot be
> justified.
>
> You seem to believe that this latter category is the empty set, which
> I must confess does greatly surprise me.

If there are already compromises are being made then why would you want to
modify the kernel for this? Some user space coding and device drivers
should be sufficient.