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Date: Fri, 24 Apr 2015 09:04:13 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: Jerome Glisse <j.glisse@gmail.com>
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        Mark Hairgrove <mhairgrove@nvidia.com>,
        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 Thu, 23 Apr 2015, Jerome Glisse wrote:

> The numa code we have today for CPU case exist because it does make
> a difference but you keep trying to restrict GPU user to a workload
> that is specific. Go talk to people doing physic, biology, data
> mining, CAD most of them do not care about latency. They have not
> hard deadline to meet with their computation. They just want things
> to compute as fast as possible and programming to be as easy as it
> can get.

I started working on the latency issues a long time ago because
performance of those labs was restricted by OS processing. A noted problem
was SLABs scanning of its objects every 2 seconds which caused pretty
significant performance regressions due to the delay of the computation in
individual threads.