refactor communication cutoff estimator. move it to Comm class. and adjust heuristics. (c098582d) · Commits · 郑智淋 / lammps

src/comm.cpp

+36 −5

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include "atom_vec.h"
		#include "force.h"
		#include "pair.h"
		#include "bond.h"
		#include "modify.h"
		#include "fix.h"
		#include "compute.h"
		@@ -585,6 +586,41 @@ void Comm::set_proc_grid(int outflag)
		}
		}

		/* ----------------------------------------------------------------------
		determine suitable communication cutoff.
		it is the maximum of the user specified value and estimates based on
		the maximum neighbor list cutoff and largest bond equilibrium length.
		we use the 1.5x the bond equilibrium distance as cutoff, if only a
		bond style exists or only bond and angle styles exists. If dihedrals
		or impropers are present we multiply by 2.0. This plus the
		"neighbor list skin" will become the default communication cutoff, if
		no pair style is defined and thus avoids all kinds of unexpected behavior
		for such systems. If a pair style exists, the result is the maximum of
		the bond based cutoff and the largest pair cutoff and the user
		specified communication cutoff.
		------------------------------------------------------------------------- */

		double Comm::get_comm_cutoff()
		{
		double maxcommcutoff = 0.0;
		if (force->bond) {
		int n = atom->nbondtypes;
		for (int i = 1; i <= n; ++i)
		maxcommcutoff = MAX(maxcommcutoff,force->bond->equilibrium_distance(i));

		if (force->dihedral \|\| force->improper) {
		maxcommcutoff *= 2.0;
		} else {
		maxcommcutoff *=1.5;
		}
		maxcommcutoff += neighbor->skin;
		}
		maxcommcutoff = MAX(maxcommcutoff,neighbor->cutneighmax);
		maxcommcutoff = MAX(maxcommcutoff,cutghostuser);

		return maxcommcutoff;
		}

		/* ----------------------------------------------------------------------
		determine which proc owns atom with coord x[3] based on current decomp
		x will be in box (orthogonal) or lamda coords (triclinic)
		@@ -963,11 +999,6 @@ rendezvous_all2all(int n, char inbuf, int insize, int inorder, int procs,
		return 0; // all nout_rvous are 0, no 2nd irregular
		}






		// create procs and outbuf for All2all if necesary

		if (!outorder) {

src/comm.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -70,6 +70,8 @@ class Comm : protected Pointers {
		void set_processors(int, char **); // set 3d processor grid attributes
		virtual void set_proc_grid(int outflag = 1); // setup 3d grid of procs

		double get_comm_cutoff(); // determine communication cutoff

		virtual void setup() = 0; // setup 3d comm pattern
		virtual void forward_comm(int dummy = 0) = 0; // forward comm of atom coords
		virtual void reverse_comm() = 0; // reverse comm of forces

src/comm_brick.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -175,7 +175,7 @@ void CommBrick::setup()
		int ntypes = atom->ntypes;
		double prd,sublo,*subhi;

		double cut = MAX(neighbor->cutneighmax,cutghostuser);
		double cut = get_comm_cutoff();
		if ((cut == 0.0) && (me == 0))
		error->warning(FLERR,"Communication cutoff is 0.0. No ghost atoms "
		"will be generated. Atoms may get lost.");

src/comm_tiled.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -157,7 +157,7 @@ void CommTiled::setup()
		// set cutoff for comm forward and comm reverse
		// check that cutoff < any periodic box length

		double cut = MAX(neighbor->cutneighmax,cutghostuser);
		double cut = get_comm_cutoff();
		if ((cut == 0.0) && (me == 0))
		error->warning(FLERR,"Communication cutoff is 0.0. No ghost atoms "
		"will be generated. Atoms may get lost.");

src/info.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -366,7 +366,7 @@ void Info::command(int narg, char **arg)
		if (comm->mode == 0) {
		fprintf(out,"Communication mode = single\n");
		fprintf(out,"Communication cutoff = %g\n",
		MAX(comm->cutghostuser,neighbor->cutneighmax));
		comm->get_comm_cutoff());
		}

		if (comm->mode == 1) {

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