From: Mark Abraham <mark.j.abraham@gmail.com>
Date: Mon, 31 Mar 2014 14:28:36 +0000 (+0200)
Subject: Fix bug accumulating nrank_pp_intranode on PME ranks
X-Git-Url: http://biod.pnpi.spb.ru/gitweb/?a=commitdiff_plain;h=0870f68b80707ce34a40ad14d2db1c7535bbfeec;p=alexxy%2Fgromacs.git

Fix bug accumulating nrank_pp_intranode on PME ranks

The old code led to cr->nrank_pp_intranode=zero on PME ranks, which
meant that a command line of mpirun -np 4 mdrun -npme 2 on a two-GPU
node would fail, because gmx_select_gpu_ids() runs on all ranks, and
it calls limit_num_gpus_used() which thinks 0 PP ranks and 2 GPUs is
silly. Adding -gpu_id 01 works, of course, but that takes a different
code path in gmx_select_gpu_ids().

Change-Id: Iecd43ef9b71e2cc0339e93724b6b1071f0a159f6
---

diff --git a/src/gromacs/gmxlib/network.c b/src/gromacs/gmxlib/network.c
index 06780b90c7..afd3ba6529 100644
--- a/src/gromacs/gmxlib/network.c
+++ b/src/gromacs/gmxlib/network.c
@@ -426,10 +426,10 @@ void gmx_init_intranode_counters(t_commrec *cr)
                 rank_intranode++;
             }
         }
-        if ((cr->duty & DUTY_PP) && num_pp[i] == mynum)
+        if (num_pp[i] == mynum)
         {
             nrank_pp_intranode++;
-            if (i < rank_world)
+            if ((cr->duty & DUTY_PP) && i < rank_world)
             {
                 rank_pp_intranode++;
             }