Merge pull request #2642 from rbberger/balance_tests

MPI balancing testing

doc/src/balance.rst

@@ -257,7 +257,7 @@ factor, similar to how the :doc:`fix balance shift <fix_balance>`
 command operates.
 
 The *dimstr* argument is a string of characters, each of which must be
-an "x" or "y" or "z".  Eacn character can appear zero or one time,
+an "x" or "y" or "z". Each character can appear zero or one time,
 since there is no advantage to balancing on a dimension more than
 once.  You should normally only list dimensions where you expect there
 to be a density variation in the particles.
@@ -285,7 +285,7 @@ plane gets closer to the target value.
 
 After the balanced plane positions are determined, if any pair of
 adjacent planes are closer together than the neighbor skin distance
-(as specified by the :doc`neigh_modify <neigh_modify>` command), then
+(as specified by the :doc:`neigh_modify <neigh_modify>` command), then
 the plane positions are shifted to separate them by at least this
 amount.  This is to prevent particles being lost when dynamics are run
 with processor sub-domains that are too narrow in one or more

doc/src/fix_balance.rst

@@ -216,7 +216,7 @@ above.  It changes the positions of cutting planes between processors
 in an iterative fashion, seeking to reduce the imbalance factor.
 
 The *dimstr* argument is a string of characters, each of which must be
-an "x" or "y" or "z".  Eacn character can appear zero or one time,
+an "x" or "y" or "z".  Each character can appear zero or one time,
 since there is no advantage to balancing on a dimension more than
 once.  You should normally only list dimensions where you expect there
 to be a density variation in the particles.

doc/utils/sphinx-config/false_positives.txt

@@ -764,7 +764,6 @@ Dyre
 Dzyaloshinskii
 Eaa
 Eaat
-Eacn
 eam
 eangle
 earg

unittest/commands/CMakeLists.txt

@@ -56,3 +56,10 @@ add_executable(test_reset_ids test_reset_ids.cpp)
 target_compile_definitions(test_reset_ids PRIVATE -DTEST_INPUT_FOLDER=${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(test_reset_ids PRIVATE lammps GTest::GMock GTest::GTest)
 add_test(NAME ResetIDs COMMAND test_reset_ids WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+
+if(BUILD_MPI)
+  add_executable(test_mpi_load_balancing test_mpi_load_balancing.cpp)
+  target_link_libraries(test_mpi_load_balancing PRIVATE lammps GTest::GTest GTest::GMock)
+  target_compile_definitions(test_mpi_load_balancing PRIVATE ${TEST_CONFIG_DEFS})
+  add_mpi_test(NAME MPILoadBalancing NUM_PROCS 4 COMMAND $<TARGET_FILE:test_mpi_load_balancing>)
+endif()

unittest/commands/test_mpi_load_balancing.cpp

@@ -0,0 +1,257 @@
+// unit tests for checking LAMMPS MPI load balancing
+
+#define LAMMPS_LIB_MPI 1
+#include "lammps.h"
+#include "atom.h"
+#include "comm.h"
+#include "domain.h"
+#include "neighbor.h"
+#include "input.h"
+#include "timer.h"
+#include "info.h"
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "../testing/test_mpi_main.h"
+
+using ::testing::ExitedWithCode;
+using ::testing::HasSubstr;
+using ::testing::StartsWith;
+using ::testing::StrEq;
+
+namespace LAMMPS_NS
+{
+
+class MPILoadBalanceTest : public ::testing::Test {
+public:
+    void command(const std::string &line) { lmp->input->one(line); }
+
+protected:
+    const char *testbinary = "LAMMPSTest";
+    LAMMPS *lmp;
+
+    void SetUp() override
+    {
+        const char *args[] = {testbinary, "-log", "none", "-echo", "screen", "-nocite"};
+        char **argv        = (char **)args;
+        int argc           = sizeof(args) / sizeof(char *);
+        if (!verbose) ::testing::internal::CaptureStdout();
+        lmp = new LAMMPS(argc, argv, MPI_COMM_WORLD);
+        InitSystem();
+        if (!verbose) ::testing::internal::GetCapturedStdout();
+    }
+
+    virtual void InitSystem()
+    {
+        command("boundary        f f f");
+        command("units           lj");
+        command("atom_style      atomic");
+        command("atom_modify     map yes");
+
+        command("region          box block 0 20 0 20 0 20");
+        command("create_box      1 box");
+        command("mass            1 1.0");
+
+
+        command("pair_style      lj/cut 2.5");
+        command("pair_coeff      1 1 1.0 1.0 2.5");
+
+        command("neighbor        0.3 bin");
+        command("neigh_modify    every 20 delay 0 check no");
+    }
+
+    void TearDown() override
+    {
+        if (!verbose) ::testing::internal::CaptureStdout();
+        delete lmp;
+        lmp = nullptr;
+        if (!verbose) ::testing::internal::GetCapturedStdout();
+    }
+};
+
+TEST_F(MPILoadBalanceTest, grid_yz)
+{
+    command("create_atoms 1 single 0 0 0");
+    command("create_atoms 1 single 0 0 5");
+    command("create_atoms 1 single 0 5 0");
+    command("create_atoms 1 single 0 5 5");
+    command("create_atoms 1 single 5 0 0");
+    command("create_atoms 1 single 5 0 5");
+    command("create_atoms 1 single 5 5 0");
+    command("create_atoms 1 single 5 5 5");
+    ASSERT_EQ(lmp->atom->natoms, 8);
+    ASSERT_EQ(lmp->comm->nprocs, 4);
+
+    // initial state
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 8);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+    }
+
+    command("balance 1 x uniform y 0.125 z uniform");
+
+    // state after balance command
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 4);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 4);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+    }
+
+    command("balance 1 x uniform y 0.125 z 0.125");
+
+    // state after second balance command
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+    }
+}
+
+TEST_F(MPILoadBalanceTest, rcb)
+{
+    command("comm_style tiled");
+    command("create_atoms 1 single 0 0 0");
+    command("create_atoms 1 single 0 0 5");
+    command("create_atoms 1 single 0 5 0");
+    command("create_atoms 1 single 0 5 5");
+    command("create_atoms 1 single 5 0 0");
+    command("create_atoms 1 single 5 0 5");
+    command("create_atoms 1 single 5 5 0");
+    command("create_atoms 1 single 5 5 5");
+
+    // initial state
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 8);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+    }
+
+    command("balance 1 rcb");
+
+    // state after balance command
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 2);
+        break;
+    }
+
+    // box dimensions should have minimal size
+    double dx = lmp->domain->subhi[0] - lmp->domain->sublo[0];
+    double dy = lmp->domain->subhi[1] - lmp->domain->sublo[1];
+    double dz = lmp->domain->subhi[2] - lmp->domain->sublo[2];
+
+    ASSERT_GT(dx, lmp->neighbor->skin);
+    ASSERT_GT(dy, lmp->neighbor->skin);
+    ASSERT_GT(dz, lmp->neighbor->skin);
+}
+
+TEST_F(MPILoadBalanceTest, rcb_min_size)
+{
+    GTEST_SKIP();
+    // TODO minimum domain size is not enforced right now
+    // skipping for now to allow other MPI tests to get merged
+    command("comm_style tiled");
+    command("create_atoms 1 single 0 0 0");
+    command("create_atoms 1 single 0 0 0.25");
+    command("create_atoms 1 single 0 0.25 0");
+    command("create_atoms 1 single 0 0.25 0.25");
+    command("create_atoms 1 single 0.25 0 0");
+    command("create_atoms 1 single 0.25 0 0.25");
+    command("create_atoms 1 single 0.25 0.25 0");
+    command("create_atoms 1 single 0.25 0.25 0.25");
+
+    // initial state
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 8);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+    }
+
+    // this should fail and not change the boxes
+    // or keep them at a minimum size
+    command("balance 1 rcb");
+
+    // state after balance command
+    switch(lmp->comm->me) {
+      case 0:
+        ASSERT_EQ(lmp->atom->nlocal, 8);
+        break;
+      case 1:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 2:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+      case 3:
+        ASSERT_EQ(lmp->atom->nlocal, 0);
+        break;
+    }
+
+    // box dimensions should have minimal size
+    double dx = lmp->domain->subhi[0] - lmp->domain->sublo[0];
+    double dy = lmp->domain->subhi[1] - lmp->domain->sublo[1];
+    double dz = lmp->domain->subhi[2] - lmp->domain->sublo[2];
+
+    ASSERT_GT(dx, lmp->neighbor->skin);
+    ASSERT_GT(dy, lmp->neighbor->skin);
+    ASSERT_GT(dz, lmp->neighbor->skin);
+}
+
+}