is LAPACK thread safe ?

[Andreas Unterkircher]

I'm using LAPACK to invert several small, symmetric matrices within my C
program. This works fine, but when I try to run these operations
concurrently by using pthreads I'm running into trouble ("floating
exception"). So far I could not detect any errors in my thread creation
procedures, so I'd like to ask if anybody knows whether LAPACK is thread
save or not. I guess yes, because all the variables are allocated outside
the LAPACk routines and then passed by reference (I'm using the routines
DPOSVX and DSYSVX).

Any hints are welcome !

Andreas

[Victor Eijkhout]

Andreas Unterkircher <unte...@ivp.bepr.ethz.ch> writes:

> Any hints are welcome !

Ask this from lap...@cs.utk.edu?

--
Victor Eijkhout
"One of the great things about books is sometimes there are some
fantastic pictures." [G.W. Bush]

[Hanyou Chu]

The current Fortran implementation of LAPACK is not thread safe.
Search for SAVE statements, for example in dlmach.f and other
files (DEFICIENCY of Fortran). Call those functions at program start
up before you start your threads.

The second option is compiler dependent. Make sure you turn thread
option on and make variables default on stack when you compile LAPACK.