<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jul 14, 2017 at 8:02 AM, Matthew Knepley <span dir="ltr"><<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span class="">On Fri, Jul 14, 2017 at 6:53 AM, Mark Adams <span dir="ltr"><<a href="mailto:mfadams@lbl.gov" target="_blank">mfadams@lbl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Karli, this would be great if you could investigate this.<div><br></div><div>A lot of this is driven by desires of DOE programs -- not your monkey not your circus -- but I think that we need to have a story for how to use GPUs, or whatever apps in our funding community want to do, and tell it dispassionately. We don't commit resources nor commit to design changes but just say this how one could do it.</div></div></blockquote><div><br></div></span><div>Mark, also note that what Patrick has done is probably the best PETSc can do on GPUs, namely polynomial smoothers and block AIJ interpolators. I think</div><div>that can all work with master right now, but you should ask him.</div></div></div></div></blockquote><div><br></div><div>Thanks Matt,</div><div><br></div><div>At this point I am just answering questions ... but if you have smoothers and interpolators (and a residual) that is all you need for the solve phase, right? These folks have a linear Poisson solve so we can amortize setup.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div><br></div><div> Matt</div><span class=""><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>The fusion folks that I work with, and I assume other DOE offices, are just looking at their codes, subroutine by subroutine, and having postdocs look at GPUising them. We just need intelligent answers to their questions. Even if we as sentient and passionate human being have opinions on the approach that is implied by their questions, it is part of my job to just give them a professional answer.</div><div><br></div><div>I have enough now (thanks Jed and Lorena, et al!) to answer the AMGx question sufficiently, and if you could give me a quick assessment of where we are with hypre's GPU solver that would be great.</div><div><br></div><div>Thanks,</div><div>Mark</div><div><br></div></div><div class="m_-5795027764280380535HOEnZb"><div class="m_-5795027764280380535h5"><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jul 13, 2017 at 11:16 PM, Karl Rupp <span dir="ltr"><<a href="mailto:rupp@iue.tuwien.ac.at" target="_blank">rupp@iue.tuwien.ac.at</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Mark,<span><br>
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I hear Hypre has support for GPUs in a May release. Any word on the status of using it in PETSc?<br>
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as far as I know, it is currently not supported in PETSc. I'll have a look at it and see what needs to be done to enable it.<span><br>
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And we discussed interfacing to AMGx, which is complicated (precluded?) by not releasing source. Anything on the potential of interfacing to AMGx? I think it would be great to make this available. It is on a lot of checkboxes. I would love to be able to say, yea you can use it.<br>
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Lorena Barba's group actually interfaced PETSc to AMGx at some point (presented at GTC 2016 if I'm not mistaken). I'll reach out to them, maybe they have something to contribute.<br>
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Best regards,<br>
Karli<br>
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</div></div></blockquote></span></div><br><br clear="all"><span class=""><div><br></div>-- <br><div class="m_-5795027764280380535gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div><div><br></div><div><a href="http://www.caam.rice.edu/~mk51/" target="_blank">http://www.caam.rice.edu/~<wbr>mk51/</a><br></div></div></div>
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