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In bjacobi.c, the following comments are given for PCCreate_BJacobi.<br>
<br>
Developer Notes: This preconditioner does not currently work with
CUDA/CUSP for a couple of
reasons.
<br>
(1) It creates seq vectors as work vectors that should be
cusp
<br>
(2) The use of VecPlaceArray() is not handled properly by CUSP (that
is it will not know where the ownership of the vector is so may use
wrong values) even if it did know the ownership it may induce extra
copy ups and downs. Satish suggests a VecTransplantArray() to handle
two vectors sharing the same pointer and handling the CUSP side as
well instead of VecGetArray()/VecPlaceArray(). <br>
<br>
<br>
I've had some success with comment (2) above in regards to
Singleblock BJacobi. I haven't yet tried it for Multiblock or
Multiproc.<br>
<br>
-Paul<br>
<br>
<blockquote
cite="mid:CAM9tzSnk8hgKg58+NKCTO2fcoDt+4Ad+towO8-5vjw9fU4v1Ww@mail.gmail.com"
type="cite">
<div class="gmail_quote">On Tue, Mar 13, 2012 at 10:18, Paul
Mullowney <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:paulm@txcorp.com">paulm@txcorp.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000">I don't think PCJACOBI
is working on the GPU yet.<br>
</div>
</blockquote>
<div><br>
</div>
<div>It damn well better be.</div>
<div><br>
</div>
<div>(It only calls MatGetDiagonal(), everything else is just a
Vec operation and the VecType will be set so that it runs on
the GPU.)</div>
<div> </div>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000"> <br>
I have some local fixes to make it work efficiently (without
extra copies), but changes won't be pushed too soon because
the design is not sufficiently general.</div>
</blockquote>
</div>
<br>
</blockquote>
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