include/thread_mpi/hwinfo.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 #ifndef _TMPI_HWINFO_H_
  39 #define _TMPI_HWINFO_H_
  40
  41 /*! \file
  42
  43   \brief CPU/core/HT count function.
  44
  45 */
  46
  47 /*! \brief Determine number of hardware threads that can be run simultaneously
  48
  49     Returns the total number of cores and SMT threads that can run.
  50
  51     \ret The maximum number of threads that can run simulataneously. If this
  52          number cannot be determined for the current architecture, -1 is
  53          returned.
  54   */
  55 int tMPI_Get_hw_nthreads(void);
  56
  57
  58 /*! \brief Determine the recommended number of hardware threads to run on
  59
  60
  61     Returns the total number of cores and SMT threads to run on. This is
  62     equal to the number of hardware threads available, or 1 if the number
  63     can't be determined, or if there are no atomics for this platform.
  64
  65     \ret The maximum number of threads to run on.
  66   */
  67 int tMPI_Get_recommended_nthreads(void);
  68
  69
  70 #endif
  71