src/gmxlib/thread_mpi/settings.h

   1 /*
   2 This source code file is part of thread_mpi.
   3 Written by Sander Pronk, Erik Lindahl, and possibly others.
   4
   5 Copyright (c) 2009, Sander Pronk, Erik Lindahl.
   6 All rights reserved.
   7
   8 Redistribution and use in source and binary forms, with or without
   9 modification, are permitted provided that the following conditions are met:
  10 1) Redistributions of source code must retain the above copyright
  11    notice, this list of conditions and the following disclaimer.
  12 2) Redistributions in binary form must reproduce the above copyright
  13    notice, this list of conditions and the following disclaimer in the
  14    documentation and/or other materials provided with the distribution.
  15 3) Neither the name of the copyright holders nor the
  16    names of its contributors may be used to endorse or promote products
  17    derived from this software without specific prior written permission.
  18
  19 THIS SOFTWARE IS PROVIDED BY US ''AS IS'' AND ANY
  20 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22 DISCLAIMED. IN NO EVENT SHALL WE BE LIABLE FOR ANY
  23 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  26 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 If you want to redistribute modifications, please consider that
  31 scientific software is very special. Version control is crucial -
  32 bugs must be traceable. We will be happy to consider code for
  33 inclusion in the official distribution, but derived work should not
  34 be called official thread_mpi. Details are found in the README & COPYING
  35 files.
  36 */
  37
  38
  39 /*#define TMPI_DEBUG*/
  40
  41
  42 /* If this is defined, thread_mpi will print a message when for every MPI
  43    call is called or returns. Useful for debugging MPI-related issues
  44    in the calling program. */
  45 /*#define TMPI_TRACE*/
  46
  47 /* if this is defined, MPI will warn/hang/crash on practices that don't conform
  48    to the MPI standard (such as not calling tMPI_Comm_free on all threads that
  49    are part of the comm being freed). */
  50 #define TMPI_STRICT
  51
  52 /* whether to warn if there are mallocs at performance-critical sections
  53    (due to preallocations being too small) */
  54 /*#define TMPI_WARN_MALLOC*/
  55
  56
  57 /* the number of envelopes to allocate per thread-to-thread path */
  58 #define N_EV_ALLOC 16
  59
  60 /* the normal maximum number of threads for pre-defined arrays
  61    (if the actual number of threads is bigger than this, it'll
  62     allocate/deallocate arrays, so no problems will arise). */
  63 #define MAX_PREALLOC_THREADS 64
  64
  65 /* Whether to use lock-free lists using compare-and-swap (cmpxchg on x86)
  66    pointer functions. Message passing using blocking Send/Recv, and multicasts
  67    are is still blocking, of course. */
  68 #define TMPI_LOCK_FREE_LISTS
  69
  70 /* Whether to disable yielding to the OS scheduler during waits. Disabling
  71    this improves performance very slightly if Nthreads<=Ncores on an
  72    otherwise idle system because waits have slightly lower latencies, but
  73    causes very poor performance if threads are competing for CPU time (for
  74    example, when Nthreads>Ncores, or another process is running on the
  75    system.
  76
  77    This option can be set with cmake. */
  78 /*#define TMPI_WAIT_FOR_NO_ONE */
  79
  80
  81
  82 /* whether to enable double-copying (where the sender copies data to an
  83    intermediate buffer for small enough buffers, allowing it to return
  84    from a blocking send call early. The receiver is free to copy from the
  85    original buffer while the sender is copying, possibly allowing them to
  86    work in parallel).
  87
  88    This option can be set with cmake. */
  89 /*#define TMPI_COPY_BUFFER*/
  90
  91
  92 /* The size (in bytes) of the maximum transmission size for which double
  93    copying is allowed (i.e. the sender doesn't wait for the receiver to
  94    become ready, but posts a copied buffer in its envelope).
  95
  96    A size of 8192 bytes was chosen after some testing with Gromacs. */
  97 #define COPY_BUFFER_SIZE 8192
  98 #ifdef TMPI_COPY_BUFFER
  99 /* We can separately specify whether we want copy buffers for send/recv or
 100    multicast communications: */
 101 #define USE_SEND_RECV_COPY_BUFFER
 102 #define USE_COLLECTIVE_COPY_BUFFER
 103 #endif
 104
 105
 106 /* The number of collective envelopes per comm object. This is the maximum
 107    number of simulataneous collective communications that can
 108    take place per comm object. If TMPI_NO_COPY_BUFFER is set, simultaneous
 109    collective communications don't happen and 2 is the right value.  */
 110 #ifdef USE_COLLECTIVE_COPY_BUFFER
 111 #define N_COLL_ENV 12
 112 #else
 113 #define N_COLL_ENV 2
 114 #endif
 115
 116
 117 /* Whether to do profiling of the number of MPI communication calls. A
 118     report with the total number of calls for each communication function
 119     will be generated at MPI_Finalize().
 120
 121     This option can be set with cmake.*/
 122 /*#define TMPI_PROFILE*/
 123
 124