Adasko's dir

[unres.git] / source / cluster / wham / src-NEWSC / work_partition.F

diff --git a/source/cluster/wham/src-NEWSC/work_partition.F b/source/cluster/wham/src-NEWSC/work_partition.F
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+#ifdef MPI
+      subroutine work_partition(lprint,ncon_work)
+c Split the conformations between processors
+      implicit none
+      include "DIMENSIONS"
+      include "sizesclu.dat"
+      include "mpif.h"
+      include "COMMON.IOUNITS"
+      include "COMMON.CLUSTER"
+      include "COMMON.MPI"
+      integer n,chunk,i,j,ii,remainder
+      integer kolor,key,ierror,errcode,ncon_work
+      logical lprint
+C
+C Divide conformations between processors; the first and
+C the last conformation to handle by ith processor is stored in 
+C indstart(i) and indend(i), respectively.
+C
+C First try to assign equal number of conformations to each processor.
+C
+        n=ncon_work
+        write (iout,*) "n=",n," nprocs=",nprocs
+        indstart(0)=1
+        chunk = N/nprocs
+        scount(0) = chunk
+c        print *,"i",0," indstart",indstart(0)," scount",
+c     &     scount(0)
+        do i=1,nprocs-1
+          indstart(i)=chunk+indstart(i-1) 
+          scount(i)=scount(i-1)
+c          print *,"i",i," indstart",indstart(i)," scount",
+c     &     scount(i)
+        enddo 
+C
+C Determine how many conformations remained yet unassigned.
+C
+        remainder=N-(indstart(nprocs-1)
+     &    +scount(nprocs-1)-1)
+c        print *,"remainder",remainder
+C
+C Assign the remainder conformations to consecutive processors, starting
+C from the lowest rank; this continues until the list is exhausted.
+C
+        if (remainder .gt. 0) then 
+          do i=1,remainder
+            scount(i-1) = scount(i-1) + 1
+            indstart(i) = indstart(i) + i
+          enddo
+          do i=remainder+1,nprocs-1
+            indstart(i) = indstart(i) + remainder
+          enddo
+        endif
+
+        indstart(nprocs)=N+1
+        scount(nprocs)=0
+
+        do i=0,NProcs
+          indend(i)=indstart(i)+scount(i)-1
+          idispl(i)=indstart(i)-1
+        enddo
+
+        N=0
+        do i=0,Nprocs-1
+          N=N+indend(i)-indstart(i)+1
+        enddo
+
+c        print *,"N",n," NCON_WORK",ncon_work
+        if (N.ne.ncon_work) then
+          write (iout,*) "!!! Checksum error on processor",me,
+     &      n,ncon_work
+          call flush(iout)
+          call MPI_Abort( MPI_COMM_WORLD, Ierror, Errcode )
+        endif
+
+      if (lprint) then
+        write (iout,*) "Partition of work between processors"
+          do i=0,nprocs-1
+            write (iout,'(a,i5,a,i7,a,i7,a,i7)')
+     &        "Processor",i," indstart",indstart(i),
+     &        " indend",indend(i)," count",scount(i)
+          enddo
+      endif
+      return
+      end
+#endif