Issue 13 in opencurrent: problem with 3D pressure solver
openc...@googlecode.com
Owner: ----
Labels: Type-Defect Priority-Medium
New issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
What steps will reproduce the problem?
1. run pcg program
2. run cubicrayleigh with Rayleigh_run()
3. run cubicrayleigh with Nusselt_run()
What is the expected output? What do you see instead?
None of them converged, and the while loop is dead
Message similar to:
[INFO] Sol_MultigridPressure3DBase::do_fmg - error after 3 iterations: L2 =
0.000000 (221243.654747x), Linf = 0.000000 (-nanx)
There is a "nan", which likely lead to segmentation faults or dead loop
What version of the product are you using? On what operating system?
Ubuntu 10.04LTS 64bit, CUDA 3.2, GTX460 Fermi
Please provide any additional information below.
I have noticed that two of the 18 unit tests failed due to segmentation
faults and it should be related to 3D pressure solver.
The unit test diagnostic info is as below.
******************************************************************
The following tests FAILED:
12 - MultigridMixedTest (SEGFAULT)
17 - PCGTest (SEGFAULT)
Errors while running CTest
make: *** [test] Error 8
******************************************************************
Thanks!
openc...@googlecode.com
Comment #1 on issue 13 by jcohen.personal: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
The "nan" is because it does not compute the Linf error, so it is undefined
(essentially, it is computing 0/0 = nan). the other errors seem real,
though.
Can you run "utest PCGDoubleTest" and post the output?
openc...@googlecode.com
Comment #2 on issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
To follow up
When checking the log file for unit tests, I found
that "LockExTest", "NSTest","ProjectDoubleTest", and "MultigridDoubleTest"
also have the similar error message "[INFO]
Sol_MultigridPressure3DBase::do_fmg - error after 8 iterations: L2 =
0.000000 (998410098814.984741x), Linf = 0.000000 (-nanx)", although they
appeared to have passed the tests.
Overall, the problem still points to the pressure solver. Does any one have
any idea?
Thanks!
openc...@googlecode.com
Comment #3 on issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
Thanks, Jonathan !
I guess I understand the error message now
I have run the two failed unit tests and the error messages are included in
the attached file.
Attachments:
Utest errors 7.2 KB
openc...@googlecode.com
Comment #4 on issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
To follow up
I think I found why MultigridMixedTest and PCGTest failed due to
segmentation fault
It seems my GTX 460 with 768M RAM is not large enough to run test with mesh
size of 256^3. Once I commented out this single test in mgmixedtest.cpp and
pcgtest.cpp, both of them can pass. Thanks!
openc...@googlecode.com
Comment #5 on issue 13 by jcohen.personal: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
Sorry, i meant to respond sooner. Yes, the tests are designed for the
Tesla cards, which have a minimum of 3GB. So these 2 larger sized tests
will fail on the 460.
I should make this an option in the build process, whether to enable these
tests or not... probably something to add to the next release.
openc...@googlecode.com
Comment #6 on issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
Thanks!
But interestingly, the MultigridDoubleTest passed the mesh size of 256^3
test. I think the memory usage of this case should be at least no less than
MultigridMixTest.
I will play with them on a C2050 later
openc...@googlecode.com
Comment #7 on issue 13 by jcohen.personal: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
No, the mixed version keeps both a single precision and double precision
copy of all grids. So it uses more memory.
openc...@googlecode.com
Comment #8 on issue 13 by yushi92: problem with 3D pressure solver
http://code.google.com/p/opencurrent/issues/detail?id=13
Okay, I see.
I should have read it more carefully. Thanks