Messages in this thread | | | Subject | Re: Interacting with coherent memory on external devices | From | Benjamin Herrenschmidt <> | Date | Thu, 23 Apr 2015 12:36:32 +1000 |
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On Wed, 2015-04-22 at 13:17 -0500, Christoph Lameter wrote: > > > But again let me stress that application that want to be in control will > > stay in control. If you want to make the decission yourself about where > > things should end up then nothing in all we are proposing will preclude > > you from doing that. Please just think about others people application, > > not just yours, they are a lot of others thing in the world and they do > > not want to be as close to the metal as you want to be. We just want to > > accomodate the largest number of use case. > > What I think you want to do is to automatize something that should not be > automatized and cannot be automatized for performance reasons.
You don't know that.
> Anyone > wanting performance (and that is the prime reason to use a GPU) would > switch this off because the latencies are otherwise not controllable and > those may impact performance severely. There are typically multiple > parallel strands of executing that must execute with similar performance > in order to allow a data exchange at defined intervals. That is no longer > possible if you add variances that come with the "transparency" here.
Stop trying to apply your unique usage model to the entire world :-)
Ben.
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