Fix div by zero in PP/PME ratio

Since we have floating pointing exceptions by default with debug
builds, these no longer ran with separate PME ranks.

Change-Id: I8b15a93901495dbde5dff959001c52ada7414008

diff --git a/src/gromacs/domdec/domdec.cpp b/src/gromacs/domdec/domdec.cpp
index 43a2d6d8541c536fd6915db41d7bb72adc728145..e593445135590e945e214a80414fbfd8b4a8baae 100644 (file)
--- a/src/gromacs/domdec/domdec.cpp
+++ b/src/gromacs/domdec/domdec.cpp
@@ -5563,7 +5563,7 @@ static float dd_f_imbal(gmx_domdec_t *dd)
 
 float dd_pme_f_ratio(gmx_domdec_t *dd)
 {
-    if (dd->comm->cycl_n[ddCyclPME] > 0)
+    if (dd->comm->load[0].mdf > 0 && dd->comm->cycl_n[ddCyclPME] > 0)
     {
         return dd->comm->load[0].pme/dd->comm->load[0].mdf;
     }