Enable GPU update for supported cases of FEP

Only mass and constraints perturbation is not supported by the
GPU constraints, hence FEP can be enabled for the rest of the cases.

Change-Id: I0ec487823ec4aeda5b09ba66a504c5358e778c8e

diff --git a/docs/release-notes/2021/major/performance.rst b/docs/release-notes/2021/major/performance.rst
index 0a72678f80f26386be4e62f7c4d387c87b4fddf5..f1053389eca953c97c3efdc63fad598d6ac91d69 100644 (file)
--- a/docs/release-notes/2021/major/performance.rst
+++ b/docs/release-notes/2021/major/performance.rst
@@ -7,3 +7,8 @@ Performance improvements
    Also, please use the syntax :issue:`number` to reference issues on redmine, without the
    a space between the colon and number!
 
+Extend supported use-cases for GPU version of update and constraints
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+GPU version of update and constraints can now be used for FEP, except mass and constraints
+free-energy perturbation.

diff --git a/docs/user-guide/mdrun-performance.rst b/docs/user-guide/mdrun-performance.rst
index 8c8e5474c9acd6ad5967f4a9cd5004ec26edbd41..ee1e4d0cbe7543df565db32a96615d838e735b8c 100644 (file)
--- a/docs/user-guide/mdrun-performance.rst
+++ b/docs/user-guide/mdrun-performance.rst
@@ -531,9 +531,10 @@ behavior.
     Setting "gpu" requires that a compatible CUDA GPU is available,
     the simulation uses a single rank.
     Update and constraints on a GPU is currently not supported
-    with domain decomposition, free-energy, virtual sites,
-    Ewald surface correction, replica exchange, constraint pulling,
-    orientation restraints and computational electrophysiology.
+    with mass and constraints free-energy perturbation, domain
+    decomposition, virtual sites, Ewald surface correction,
+    replica exchange, constraint pulling, orientation restraints
+    and computational electrophysiology.
 
 ``-gpu_id``
     A string that specifies the ID numbers of the GPUs that

diff --git a/src/gromacs/mdrun/md.cpp b/src/gromacs/mdrun/md.cpp
index 91d932e3d8fd286f28cb7529523cc371f19e1cbc..7e2e98f648e397366d07b740ae6eaec5ba537438 100644 (file)
--- a/src/gromacs/mdrun/md.cpp
+++ b/src/gromacs/mdrun/md.cpp
@@ -353,8 +353,11 @@ void gmx::LegacySimulator::do_md()
                            "Constraints pulling is not supported with the GPU update.\n");
         GMX_RELEASE_ASSERT(fcd->orires.nr == 0,
                            "Orientation restraints are not supported with the GPU update.\n");
-        GMX_RELEASE_ASSERT(ir->efep == efepNO,
-                           "Free energy perturbations are not supported with the GPU update.");
+        GMX_RELEASE_ASSERT(
+                ir->efep == efepNO
+                        || (!haveFreeEnergyType(*ir, efptBONDED) && !haveFreeEnergyType(*ir, efptMASS)),
+                "Free energy perturbation of masses and constraints are not supported with the GPU "
+                "update.");
         GMX_RELEASE_ASSERT(graph == nullptr, "The graph is not supported with GPU update.");
 
         if (constr != nullptr && constr->numConstraintsTotal() > 0)

diff --git a/src/gromacs/mdtypes/inputrec.cpp b/src/gromacs/mdtypes/inputrec.cpp
index 6f6e386f963f850c023d11b15babe848892b05b7..a57b89d6da8c3a5ddd18095e12e9affa8ff09987 100644 (file)
--- a/src/gromacs/mdtypes/inputrec.cpp
+++ b/src/gromacs/mdtypes/inputrec.cpp
@@ -1575,3 +1575,15 @@ bool haveEwaldSurfaceContribution(const t_inputrec& ir)
 {
     return EEL_PME_EWALD(ir.coulombtype) && (ir.ewald_geometry == eewg3DC || ir.epsilon_surface != 0);
 }
+
+bool haveFreeEnergyType(const t_inputrec& ir, const int fepType)
+{
+    for (int i = 0; i < ir.fepvals->n_lambda; i++)
+    {
+        if (ir.fepvals->all_lambda[fepType][i] > 0)
+        {
+            return true;
+        }
+    }
+    return false;
+}

diff --git a/src/gromacs/mdtypes/inputrec.h b/src/gromacs/mdtypes/inputrec.h
index 4659516b558fb08d469f7bb7768ecb13405ec12a..b7a903accf0b528f2d96824e383c9d58bdb10b1f 100644 (file)
--- a/src/gromacs/mdtypes/inputrec.h
+++ b/src/gromacs/mdtypes/inputrec.h
@@ -700,4 +700,13 @@ real maxReferenceTemperature(const t_inputrec& ir);
  */
 bool haveEwaldSurfaceContribution(const t_inputrec& ir);
 
+/*! \brief Check if calculation of the specific FEP type was requested.
+ *
+ * \param[in] ir       Input record.
+ * \param[in] fepType  Free-energy perturbation type to check for.
+ *
+ * \returns If the \p fepType is perturbed in this run.
+ */
+bool haveFreeEnergyType(const t_inputrec& ir, int fepType);
+
 #endif /* GMX_MDTYPES_INPUTREC_H */

diff --git a/src/gromacs/taskassignment/decidegpuusage.cpp b/src/gromacs/taskassignment/decidegpuusage.cpp
index d8fa6a93e9f71c6510c18af4eb3971d2cd67365a..b6659b2e7b4adc8a048a8203a3dd885b68a89da7 100644 (file)
--- a/src/gromacs/taskassignment/decidegpuusage.cpp
+++ b/src/gromacs/taskassignment/decidegpuusage.cpp
@@ -630,10 +630,10 @@ bool decideWhetherToUseGpuForUpdate(const bool           forceGpuUpdateDefault,
         // The graph is needed, but not supported
         errorMessage += "Orientation restraints are not supported.\n";
     }
-    if (inputrec.efep != efepNO)
+    if (inputrec.efep != efepNO
+        && (haveFreeEnergyType(inputrec, efptBONDED) || haveFreeEnergyType(inputrec, efptMASS)))
     {
-        // Actually all free-energy options except for mass and constraint perturbation are supported
-        errorMessage += "Free energy perturbations are not supported.\n";
+        errorMessage += "Free energy perturbation for mass and constraints are not supported.\n";
     }
     const auto particleTypes = gmx_mtop_particletype_count(mtop);
     if (particleTypes[eptShell] > 0)