ABINIT Discussion Forums

Hello - in the mpi distribution of k and bands over the processors (src/57_iovars/mpi_setup1.F90) there is the following around line 430:

! If the number of bands was estimated, there might be a side effect
! when the definitive number of bands is known. k points
! might be attributed to different processors than the present
! proc_distrb describes. At most, the number of k points could
! increase by 1 ...
if(tnband==0)nkpt_me=nkpt_me+1

This is horrendous!!!! If I try to parallelize fully over k (mkmem=1) and do not specify nband in the input file the code sets mkmem=2, and doubles my memory usage. This in unacceptable. The final number of bands should be determined with certainty before distribution, not fudging things with safety margins that potentially double memory footprint! We need some serious cleaning of the distribution routine, perhaps with separate, clearer, subroutines for each case (GS, RF ...). I do not dare modify this line, which probably came from a bug with implicit estimation of the nband - could someone have a look at it?

ciao!

Matthieu

Dear Matthieu,

These lines are very old (before Abinit-5.1.2 !) and were initially in invars1.F90. I have only moved them to mpi_setup1.F90 without changing anything. I intend to rationalize mpi_setup1 in a next future and I shall try to understand where it comes from at that moment.

Sincerely yours

François