>> > Dear all > > I allocated the memory exactly with symbolic computation, and tried > preallocation on AIJ and SBAIJ, it works well for AIJ, no additional > allocaiton is needed in assembly... then I did it on SBAIJ ( nonzeros of > upper triangular part + 1), the performance is much worse , it seems that > memory allocation was still needed... does anyone have such problem before?
May I have the segment of your code that implements the memory allocation? I'll test it and see what is the problem. BTW, you may send this type of request to petsc-maint at mcs.anl.gov instead of petsc-users. Hong > > Thank you > Best regards > Zhifeng Sheng > > > > > > >
