/* check whether an 'nst'-style parameter p is a multiple of nst, and
set it to be one if not, with a warning. */
static void check_nst_param(const gmx::MDLogger &mdlog,
const char *desc_nst, int nst,
const char *desc_p, int *p)
{
if (*p > 0 && *p % nst != 0)
{
/* Round up to the next multiple of nst */
*p = ((*p)/nst + 1)*nst;
GMX_LOG(mdlog.warning).asParagraph().appendTextFormatted(
"NOTE: %s changes %s to %d", desc_nst, desc_p, *p);
}
}
void gmx_omp_nthreads_read_env(const gmx::MDLogger &mdlog,
int *nthreads_omp)
{
char *env;
gmx_bool bCommandLineSetNthreadsOMP = *nthreads_omp > 0;
char buffer[STRLEN];
GMX_RELEASE_ASSERT(nthreads_omp, "nthreads_omp must be a non-NULL pointer");
if ((env = getenv("OMP_NUM_THREADS")) != nullptr)
{
int nt_omp;
sscanf(env, "%d", &nt_omp);
if (nt_omp <= 0)
{
gmx_fatal(FARGS, "OMP_NUM_THREADS is invalid: '%s'", env);
}
if (bCommandLineSetNthreadsOMP && nt_omp != *nthreads_omp)
{
gmx_fatal(FARGS, "Environment variable OMP_NUM_THREADS (%d) and the number of threads requested on the command line (%d) have different values. Either omit one, or set them both to the same value.", nt_omp, *nthreads_omp);
}
/* Setting the number of OpenMP threads. */
*nthreads_omp = nt_omp;
/* Output the results */
sprintf(buffer,
"\nThe number of OpenMP threads was set by environment variable OMP_NUM_THREADS to %d%s\n\n",
nt_omp,
bCommandLineSetNthreadsOMP ? " (and the command-line setting agreed with that)" : "");
/* This prints once per simulation for multi-simulations,
* which might help diagnose issues with inhomogenous
* cluster setups. */
GMX_LOG(mdlog.info).appendTextFormatted("%s", buffer);
if (debug)
{
/* This prints once per process for real MPI (i.e. once
* per debug file), and once per simulation for thread MPI
* (because of logic in the calling function). */
fputs(buffer, debug);
}
}
}
int check_nstglobalcomm(const gmx::MDLogger &mdlog, int nstglobalcomm, t_inputrec *ir)
{
if (!EI_DYNAMICS(ir->eI))
{
nstglobalcomm = 1;
}
if (nstglobalcomm == -1)
{
// Set up the default behaviour
if (!(ir->nstcalcenergy > 0 ||
ir->nstlist > 0 ||
ir->etc != etcNO ||
ir->epc != epcNO))
{
/* The user didn't choose the period for anything
important, so we just make sure we can send signals and
write output suitably. */
nstglobalcomm = 10;
if (ir->nstenergy > 0 && ir->nstenergy < nstglobalcomm)
{
nstglobalcomm = ir->nstenergy;
}
}
else
{
/* The user has made a choice (perhaps implicitly), so we
* ensure that we do timely intra-simulation communication
* for (possibly) each of the four parts that care.
*
* TODO Does the Verlet scheme (+ DD) need any
* communication at nstlist steps? Is the use of nstlist
* here a leftover of the twin-range scheme? Can we remove
* nstlist when we remove the group scheme?
*/
nstglobalcomm = lcd4(ir->nstcalcenergy,
ir->nstlist,
ir->etc != etcNO ? ir->nsttcouple : 0,
ir->epc != epcNO ? ir->nstpcouple : 0);
}
}
else
{
// Check that the user's choice of mdrun -gcom will work
if (ir->nstlist > 0 &&
nstglobalcomm > ir->nstlist && nstglobalcomm % ir->nstlist != 0)
{
nstglobalcomm = (nstglobalcomm / ir->nstlist)*ir->nstlist;
GMX_LOG(mdlog.warning).asParagraph().appendTextFormatted(
"WARNING: nstglobalcomm is larger than nstlist, but not a multiple, setting it to %d",
nstglobalcomm);
}
if (ir->nstcalcenergy > 0)
{
check_nst_param(mdlog, "-gcom", nstglobalcomm,
"nstcalcenergy", &ir->nstcalcenergy);
}
if (ir->etc != etcNO && ir->nsttcouple > 0)
{
check_nst_param(mdlog, "-gcom", nstglobalcomm,
"nsttcouple", &ir->nsttcouple);
}
if (ir->epc != epcNO && ir->nstpcouple > 0)
{
check_nst_param(mdlog, "-gcom", nstglobalcomm,
"nstpcouple", &ir->nstpcouple);
}
check_nst_param(mdlog, "-gcom", nstglobalcomm,
"nstenergy", &ir->nstenergy);
check_nst_param(mdlog, "-gcom", nstglobalcomm,
"nstlog", &ir->nstlog);
}
if (ir->comm_mode != ecmNO && ir->nstcomm < nstglobalcomm)
{
GMX_LOG(mdlog.warning).asParagraph().appendTextFormatted(
"WARNING: Changing nstcomm from %d to %d",
ir->nstcomm, nstglobalcomm);
ir->nstcomm = nstglobalcomm;
}
GMX_LOG(mdlog.info).appendTextFormatted(
"Intra-simulation communication will occur every %d steps.\n", nstglobalcomm);
return nstglobalcomm;
}
/*! \brief Report on the OpenMP settings that will be used */
static void
reportOpenmpSettings(const gmx::MDLogger &mdlog,
const t_commrec *cr,
gmx_bool bOMP,
gmx_bool bFullOmpSupport,
gmx_bool bSepPME)
{
#if GMX_THREAD_MPI
const char *mpi_str = "per tMPI thread";
#else
const char *mpi_str = "per MPI process";
#endif
int nth_min, nth_max, nth_pme_min, nth_pme_max;
/* inform the user about the settings */
if (!bOMP)
{
return;
}
#if GMX_MPI
if (cr->nnodes + cr->npmenodes > 1)
{
/* Get the min and max thread counts over the MPI ranks */
int buf_in[4], buf_out[4];
buf_in[0] = -modth.gnth;
buf_in[1] = modth.gnth;
buf_in[2] = -modth.gnth_pme;
buf_in[3] = modth.gnth_pme;
MPI_Allreduce(buf_in, buf_out, 4, MPI_INT, MPI_MAX, cr->mpi_comm_mysim);
nth_min = -buf_out[0];
nth_max = buf_out[1];
nth_pme_min = -buf_out[2];
nth_pme_max = buf_out[3];
}
else
#endif
{
nth_min = modth.gnth;
nth_max = modth.gnth;
nth_pme_min = modth.gnth_pme;
nth_pme_max = modth.gnth_pme;
}
/* for group scheme we print PME threads info only */
if (bFullOmpSupport)
{
if (nth_max == nth_min)
{
GMX_LOG(mdlog.warning).appendTextFormatted(
"Using %d OpenMP thread%s %s",
nth_min, nth_min > 1 ? "s" : "",
cr->nnodes > 1 ? mpi_str : "");
}
else
{
GMX_LOG(mdlog.warning).appendTextFormatted(
"Using %d - %d OpenMP threads %s",
nth_min, nth_max, mpi_str);
}
}
if (bSepPME && (nth_pme_min != nth_min || nth_pme_max != nth_max))
{
if (nth_pme_max == nth_pme_min)
{
GMX_LOG(mdlog.warning).appendTextFormatted(
"Using %d OpenMP thread%s %s for PME",
nth_pme_min, nth_pme_min > 1 ? "s" : "",
cr->nnodes > 1 ? mpi_str : "");
}
else
{
GMX_LOG(mdlog.warning).appendTextFormatted(
"Using %d - %d OpenMP threads %s for PME",
nth_pme_min, nth_pme_max, mpi_str);
}
}
GMX_LOG(mdlog.warning);
}
/** Determine the number of threads for module \p mod.
*
* \p m takes values form the module_nth_t enum and maps these to the
* corresponding value in modth_env_var.
*
* Each number of threads per module takes the default value unless
* GMX_*_NUM_THERADS env var is set, case in which its value overrides
* the deafult.
*
* The "group" scheme supports OpenMP only in PME and in thise case all but
* the PME nthread values default to 1.
*/
static void pick_module_nthreads(const gmx::MDLogger &mdlog, int m,
gmx_bool bFullOmpSupport,
gmx_bool bSepPME)
{
char *env;
int nth;
const bool bOMP = GMX_OPENMP;
/* The default should never be set through a GMX_*_NUM_THREADS env var
* as it's always equal with gnth. */
if (m == emntDefault)
{
return;
}
/* check the environment variable */
if ((env = getenv(modth_env_var[m])) != nullptr)
{
sscanf(env, "%d", &nth);
if (!bOMP)
{
gmx_warning("%s=%d is set, but %s is compiled without OpenMP!",
modth_env_var[m], nth,
gmx::getProgramContext().displayName());
}
/* with the verlet codepath, when any GMX_*_NUM_THREADS env var is set,
* OMP_NUM_THREADS also has to be set */
if (bFullOmpSupport && getenv("OMP_NUM_THREADS") == nullptr)
{
gmx_warning("%s=%d is set, the default number of threads also "
"needs to be set with OMP_NUM_THREADS!",
modth_env_var[m], nth);
}
/* with the group scheme warn if any env var except PME is set */
if (!bFullOmpSupport)
{
if (m != emntPME)
{
gmx_warning("%s=%d is set, but OpenMP multithreading is not "
"supported in %s!",
modth_env_var[m], nth, mod_name[m]);
nth = 1;
}
}
/* only babble if we are really overriding with a different value */
if ((bSepPME && m == emntPME && nth != modth.gnth_pme) || (nth != modth.gnth))
{
GMX_LOG(mdlog.warning).asParagraph().appendTextFormatted(
"%s=%d set, overriding the default number of %s threads",
modth_env_var[m], nth, mod_name[m]);
}
}
else
{
/* pick the global PME node nthreads if we are setting the number
* of threads in separate PME nodes */
nth = (bSepPME && m == emntPME) ? modth.gnth_pme : modth.gnth;
}
gmx_omp_nthreads_set(m, nth);
}
