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--- doku:time [2015/04/02 14:20] – [MPI_WTIME()] ir
+++ doku:time [2015/04/17 11:45] (current) – [Hybrid OMP and MPI] ir
@@ Line 5: / Line 5: @@
 [[http://www.mpi-forum.org/docs/mpi-3.0/mpi30-report.pdf|mpi-3.0 Standard]].).
-==== MPI_WTIME() ====
+==== MPI internal functions ====
+=== MPI_WTIME() ===
 <code>
 double MPI_Wtime(void)
@@ Line 26: / Line 28: @@
 otherwise its behavior is undefined.
-==== MPI_WTICK() ====
+=== MPI_WTICK() ===
 <code>double MPI_Wtick(void)
 DOUBLE PRECISION MPI_Wtick() BIND(C)
@@ Line 32: / Line 34: @@
 MPI_WTICK returns the resolution of MPI_WTIME in seconds, i.e. the time between successive clock ticks given in seconds.
-==== omp_get_wtime ====
+=== Examples ===
+In this  {{:doku:mpitime.c|example file}}, t1=MPI_WTIME() and t2=MPI_WTIME() enclose the region wich should be timed.
+There are two possibilities. Either a MPI_Barrier can be set before each time call. Then the time measured is the time needed that all MPI processes are finished. Or t1 and t2 are defined without a barrier, yielding the execution times for the individual processes.
+==== omp internal calls ====
+=== omp_get_wtime ===
 c example:
@@ Line 48: / Line 54: @@
 gives the amount of time that the CPU is busy for a particular task from one call to the next.
+===== Hybrid OMP and MPI ======
+{{ :doku:mpi_omp:hybrid.png?400 |}}
+{{ :doku:mpi_omp:hybridbarrier.png?400 |}}
+{{:doku:mpi_omp:hybridtime.c|}}
+====== Serial codes ======
 ==== fortran ====
 <code>