blob: ccf28134ca402b6c177deb7d01bef4f6fa586de5 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
/* Copyright 2020 Axel Huebl
*
* This file is part of WarpX.
*
* License: BSD-3-Clause-LBNL
*/
#include "MPIInitHelpers.H"
#include <AMReX.H>
#include <AMReX_ParallelDescriptor.H>
#include <AMReX_Print.H>
#include <string>
#include <utility>
namespace utils
{
std::pair< int, int >
warpx_mpi_init (int argc, char* argv[])
{
int thread_required = -1;
int thread_provided = -1;
#ifdef AMREX_USE_MPI
thread_required = MPI_THREAD_SINGLE; // equiv. to MPI_Init
# ifdef AMREX_USE_OMP
thread_required = MPI_THREAD_FUNNELED;
# endif
# ifdef AMREX_MPI_THREAD_MULTIPLE // i.e. for async_io
thread_required = MPI_THREAD_MULTIPLE;
# endif
MPI_Init_thread(&argc, &argv, thread_required, &thread_provided);
#endif
return std::make_pair(thread_required, thread_provided);
}
void
warpx_check_mpi_thread_level (std::pair< int, int > const mpi_thread_levels)
{
#ifdef AMREX_USE_MPI
auto const thread_required = mpi_thread_levels.first;
auto const thread_provided = mpi_thread_levels.second;
auto mtn = amrex::ParallelDescriptor::mpi_level_to_string;
if( thread_provided < thread_required )
amrex::Print() << "WARNING: Provided MPI thread safety level ("
<< mtn(thread_provided) << ") is LOWER than requested "
<< mtn(thread_required) << "). This might lead to undefined "
<< "results in asynchronous operations (e.g. async_io).";
if( thread_provided > thread_required )
amrex::Print() << "NOTE: Provided MPI thread safety level ("
<< mtn(thread_provided) << ") is stricter than requested "
<< mtn(thread_required) << "). This might reduce multi-node "
<< "communication performance.";
#endif
}
} // namespace utils
|
