void pme_loadbal_do(pme_load_balancing_t *pme_lb,
t_commrec *cr,
FILE *fp_err,
FILE *fp_log,
t_inputrec *ir,
t_forcerec *fr,
t_state *state,
gmx_wallcycle_t wcycle,
gmx_int64_t step,
gmx_int64_t step_rel,
gmx_bool *bPrinting)
{
int n_prev;
double cycles_prev;
assert(pme_lb != NULL);
if (!pme_lb->bActive)
{
return;
}
n_prev = pme_lb->cycles_n;
cycles_prev = pme_lb->cycles_c;
wallcycle_get(wcycle, ewcSTEP, &pme_lb->cycles_n, &pme_lb->cycles_c);
if (pme_lb->cycles_n == 0)
{
/* Before the first step we haven't done any steps yet */
return;
}
/* Sanity check, we expect nstlist cycle counts */
if (pme_lb->cycles_n - n_prev != ir->nstlist)
{
/* We could return here, but it's safer to issue and error and quit */
gmx_incons("pme_loadbal_do called at an interval != nstlist");
}
/* PME grid + cut-off optimization with GPUs or PME ranks */
if (!pme_lb->bBalance && pme_lb->bSepPMERanks)
{
if (pme_lb->bTriggerOnDLB)
{
pme_lb->bBalance = dd_dlb_is_on(cr->dd);
}
/* We should ignore the first timing to avoid timing allocation
* overhead. And since the PME load balancing is called just
* before DD repartitioning, the ratio returned by dd_pme_f_ratio
* is not over the last nstlist steps, but the nstlist steps before
* that. So the first useful ratio is available at step_rel=3*nstlist.
*/
else if (step_rel >= 3*ir->nstlist)
{
if (DDMASTER(cr->dd))
{
/* If PME rank load is too high, start tuning */
pme_lb->bBalance =
(dd_pme_f_ratio(cr->dd) >= loadBalanceTriggerFactor);
}
dd_bcast(cr->dd, sizeof(gmx_bool), &pme_lb->bBalance);
}
pme_lb->bActive = (pme_lb->bBalance ||
step_rel <= pme_lb->step_rel_stop);
}
/* The location in the code of this balancing termination is strange.
* You would expect to have it after the call to pme_load_balance()
* below, since there pme_lb->stage is updated.
* But when terminating directly after deciding on and selecting the
* optimal setup, DLB will turn on right away if it was locked before.
* This might be due to PME reinitialization. So we check stage here
* to allow for another nstlist steps with DLB locked to stabilize
* the performance.
*/
if (pme_lb->bBalance && pme_lb->stage == pme_lb->nstage)
{
pme_lb->bBalance = FALSE;
if (DOMAINDECOMP(cr) && dd_dlb_is_locked(cr->dd))
{
/* Unlock the DLB=auto, DLB is allowed to activate */
dd_dlb_unlock(cr->dd);
md_print_warn(cr, fp_log, "NOTE: DLB can now turn on, when beneficial\n");
/* We don't deactivate the tuning yet, since we will balance again
* after DLB gets turned on, if it does within PMETune_period.
*/
continue_pme_loadbal(pme_lb, TRUE);
pme_lb->bTriggerOnDLB = TRUE;
pme_lb->step_rel_stop = step_rel + PMETunePeriod*ir->nstlist;
}
else
{
/* We're completely done with PME tuning */
pme_lb->bActive = FALSE;
}
if (DOMAINDECOMP(cr))
{
/* Set the cut-off limit to the final selected cut-off,
* so we don't have artificial DLB limits.
* This also ensures that we won't disable the currently
* optimal setting during a second round of PME balancing.
*/
set_dd_dlb_max_cutoff(cr, fr->ic->rlistlong);
}
}
if (pme_lb->bBalance)
{
/* We might not have collected nstlist steps in cycles yet,
* since init_step might not be a multiple of nstlist,
* but the first data collected is skipped anyhow.
*/
pme_load_balance(pme_lb, cr,
fp_err, fp_log,
ir, state, pme_lb->cycles_c - cycles_prev,
fr->ic, fr->nbv, &fr->pmedata,
step);
/* Update constants in forcerec/inputrec to keep them in sync with fr->ic */
fr->ewaldcoeff_q = fr->ic->ewaldcoeff_q;
fr->ewaldcoeff_lj = fr->ic->ewaldcoeff_lj;
fr->rlist = fr->ic->rlist;
fr->rlistlong = fr->ic->rlistlong;
fr->rcoulomb = fr->ic->rcoulomb;
fr->rvdw = fr->ic->rvdw;
if (ir->eDispCorr != edispcNO)
{
calc_enervirdiff(NULL, ir->eDispCorr, fr);
}
}
if (!pme_lb->bBalance &&
(!pme_lb->bSepPMERanks || step_rel > pme_lb->step_rel_stop))
{
/* We have just deactivated the balancing and we're not measuring PP/PME
* imbalance during the first steps of the run: deactivate the tuning.
*/
pme_lb->bActive = FALSE;
}
if (!(pme_lb->bActive) && DOMAINDECOMP(cr) && dd_dlb_is_locked(cr->dd))
{
/* Make sure DLB is allowed when we deactivate PME tuning */
dd_dlb_unlock(cr->dd);
md_print_warn(cr, fp_log, "NOTE: DLB can now turn on, when beneficial\n");
}
*bPrinting = pme_lb->bBalance;
}
void pme_loadbal_do(pme_load_balancing_t *pme_lb,
t_commrec *cr,
FILE *fp_err,
FILE *fp_log,
t_inputrec *ir,
t_forcerec *fr,
t_state *state,
gmx_wallcycle_t wcycle,
gmx_int64_t step,
gmx_int64_t step_rel,
gmx_bool *bPrinting)
{
int n_prev;
double cycles_prev;
assert(pme_lb != NULL);
if (!pme_lb->bActive)
{
return;
}
n_prev = pme_lb->cycles_n;
cycles_prev = pme_lb->cycles_c;
wallcycle_get(wcycle, ewcSTEP, &pme_lb->cycles_n, &pme_lb->cycles_c);
if (pme_lb->cycles_n == 0)
{
/* Before the first step we haven't done any steps yet */
return;
}
/* Sanity check, we expect nstlist cycle counts */
if (pme_lb->cycles_n - n_prev != ir->nstlist)
{
/* We could return here, but it's safer to issue and error and quit */
gmx_incons("pme_loadbal_do called at an interval != nstlist");
}
/* PME grid + cut-off optimization with GPUs or PME ranks */
if (!pme_lb->bBalance && pme_lb->bSepPMERanks)
{
if (DDMASTER(cr->dd))
{
/* PME rank load is too high, start tuning */
pme_lb->bBalance = (dd_pme_f_ratio(cr->dd) >= loadBalanceTriggerFactor);
}
dd_bcast(cr->dd, sizeof(gmx_bool), &pme_lb->bBalance);
if (pme_lb->bBalance &&
use_GPU(fr->nbv) && DOMAINDECOMP(cr) &&
pme_lb->bSepPMERanks)
{
/* Lock DLB=auto to off (does nothing when DLB=yes/no).
* With GPUs + separate PME ranks, we don't want DLB.
* This could happen when we scan coarse grids and
* it would then never be turned off again.
* This would hurt performance at the final, optimal
* grid spacing, where DLB almost never helps.
* Also, DLB can limit the cut-off for PME tuning.
*/
dd_dlb_set_lock(cr->dd, TRUE);
}
}
if (pme_lb->bBalance)
{
/* init_step might not be a multiple of nstlist,
* but the first cycle is always skipped anyhow.
*/
pme_lb->bBalance =
pme_load_balance(pme_lb, cr,
fp_err, fp_log,
ir, state, pme_lb->cycles_c - cycles_prev,
fr->ic, fr->nbv, &fr->pmedata,
step);
/* Update constants in forcerec/inputrec to keep them in sync with fr->ic */
fr->ewaldcoeff_q = fr->ic->ewaldcoeff_q;
fr->ewaldcoeff_lj = fr->ic->ewaldcoeff_lj;
fr->rlist = fr->ic->rlist;
fr->rlistlong = fr->ic->rlistlong;
fr->rcoulomb = fr->ic->rcoulomb;
fr->rvdw = fr->ic->rvdw;
if (ir->eDispCorr != edispcNO)
{
calc_enervirdiff(NULL, ir->eDispCorr, fr);
}
if (!pme_lb->bBalance &&
DOMAINDECOMP(cr) &&
dd_dlb_is_locked(cr->dd))
{
/* Unlock the DLB=auto, DLB is allowed to activate
* (but we don't expect it to activate in most cases).
*/
dd_dlb_set_lock(cr->dd, FALSE);
}
}
if (!pme_lb->bBalance &&
(!pme_lb->bSepPMERanks || (step_rel <= PMETunePeriod*ir->nstlist)))
{
/* We have just deactivated the balancing and we're not measuring PP/PME
* imbalance during the first 50*nstlist steps: deactivate the tuning.
*/
pme_lb->bActive = FALSE;
}
*bPrinting = pme_lb->bBalance;
}
