On Sat, 22 Oct 2011, Wen Jiang wrote:

> I am wondering what does exactly 'semiparallel_only()' mean in the
> petsc_matrix.c file.

See the comment above its definition in the petsc_matrix.h file:

// Macro to identify and debug functions which should be called in
// parallel on parallel matrices but which may be called in serial on
// serial matrices.

In other words: if you have a parallel sparse matrix M, and you call
something like M.l1_norm() on processors 1, 2, and 3, then you'd
better also be calling M.l1_norm() at the same time on processor 4 if
you don't want your program to die or lock up.  semiparallel_only() is
an attempt (how good an attempt depends on what processor 4 is doing
instead and what your MPI stack does on certain errors) to exit such
situations with more informative output.
---
Roy

------------------------------------------------------------------------------
The demand for IT networking professionals continues to grow, and the
demand for specialized networking skills is growing even more rapidly.
Take a complimentary Learning@Cisco Self-Assessment and learn 
about Cisco certifications, training, and career opportunities. 
http://p.sf.net/sfu/cisco-dev2dev
_______________________________________________
Libmesh-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/libmesh-users

Reply via email to