Need help on cgesvd

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Need help on cgesvd

Postby hmli » Sun Oct 28, 2012 11:34 pm

testing_cgesvd completes successfully for some sizes but fails for some other.
Code: Select all
/magma-1.2.1/testing> ./testing_cgesvd -M 256 -N 1800
device 0: GeForce GT 640, 901.5 MHz clock, 2047.7 MB memory, capability 3.0
  testing_cgesvd -M 256 -N 1800

  N     CPU Time(s)    GPU Time(s)     ||R||_F / ||A||_F
==========================================================
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
CUBLAS error: memory mapping error (11) in magma_cgetmatrix_async at cset_get.cpp:145
CUBLAS error: memory mapping error (11) in magma_csetmatrix at cset_get.cpp:98
 1800       4.38           4.32         4.211870e-01

I tested it on GT640, C1060 and GTX670 and replicated the same error. I traced the error to cgebrd() function, which by itself passed tests. The magma module was built on mkl. I rebulit magma with gcc instead of icc ( the mkl lib was still built by icc though) but the error was still there. Any suggestions?
hmli
 
Posts: 3
Joined: Wed Oct 24, 2012 3:12 am

Re: Need help on cgesvd

Postby mgates3 » Wed Oct 31, 2012 11:15 am

This is an error that we recently found. For [zc]gesvd, if you allocate the workspace of size
(M+N)*nb + 2*min(M,N) + 2*min(M,N)**2
it should work. There's a more involved fix to allow using the smaller workspace of size
(M+N)*nb + 2*min(M,N)
with reduced performance.

Note: for [ds]gesvd, in both cases the workspace requires 3*min(M,N) instead of 2*min(M,N), since it doesn't take rwork separately.

-mark
mgates3
 
Posts: 416
Joined: Fri Jan 06, 2012 2:13 pm

Re: Need help on cgesvd

Postby hmli » Thu Nov 01, 2012 3:27 am

Yes, That is the problem; now it works.
Thank you, mark!
hmli
 
Posts: 3
Joined: Wed Oct 24, 2012 3:12 am


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