From cdfb989473e1a0b379e171bc6242f4e742c4d563 Mon Sep 17 00:00:00 2001
From: Aaron Donahue <donahue.aaron@gmail.com>
Date: Wed, 12 Apr 2017 16:33:40 -0700
Subject: [PATCH] Fixed bug where seg fault occurs when dyn_npes < npes

Fixed a bug which resulted in a segmentation fault for simulations with
fewer dynamics processors (dyn_npes) than total processors (npes).
	* Fix skips a call to createmetadata subroutine which is associated
          with a certain type of mapping file in ESMF for processors not
          doing dynamics.
	* Slightly related fix to gravity_wave_sources code which called boundary
          exchange for processors not neccesarily associated with dynamics.

[BFB] - Bit-For-Bit
---
 components/cam/src/dynamics/se/dyn_comp.F90              | 6 +++++-
 components/cam/src/dynamics/se/gravity_waves_sources.F90 | 9 ++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/components/cam/src/dynamics/se/dyn_comp.F90 b/components/cam/src/dynamics/se/dyn_comp.F90
index 9bd95fe3291a..ccbc9ccae79e 100644
--- a/components/cam/src/dynamics/se/dyn_comp.F90
+++ b/components/cam/src/dynamics/se/dyn_comp.F90
@@ -50,6 +50,8 @@ Module dyn_comp
   ! !REVISION HISTORY:
   !
   !  JPE  06.05.31:  created
+  !  Aaron Donahue 17.04.11: Fixed bug in write_grid_mapping which caused 
+  !       a segmentation fault when dyn_npes<npes
   !
   !----------------------------------------------------------------------
 
@@ -444,7 +446,9 @@ subroutine write_grid_mapping(par, elem)
        ierr = pio_def_var(nc, 'element_corners', PIO_INT, (/dim1,dim2/),vid)
     
        ierr = pio_enddef(nc)
-       call createmetadata(par, elem, subelement_corners)
+       if (iam<par%nprocs) then
+          call createmetadata(par, elem, subelement_corners)
+       end if
 
        jj=0
        do cc=0,3
diff --git a/components/cam/src/dynamics/se/gravity_waves_sources.F90 b/components/cam/src/dynamics/se/gravity_waves_sources.F90
index fd6201a5cc68..3e6b97baa0ed 100644
--- a/components/cam/src/dynamics/se/gravity_waves_sources.F90
+++ b/components/cam/src/dynamics/se/gravity_waves_sources.F90
@@ -100,6 +100,9 @@ subroutine compute_frontogenesis(frontgf,frontga,tl,elem,ederiv,hybrid,nets,nete
   ! Change by Santos, 10 Aug 2011:
   ! Integrated into gravity_waves_sources module, several arguments made global
   !  to prevent repeated allocation/initialization
+  ! Change by Aaron Donahue, April 2017:
+  !   Fixed bug where boundary information was called for processors not associated
+  !   with dynamics when dyn_npes<npes
   ! 
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     use physical_constants, only : kappa
@@ -107,6 +110,8 @@ subroutine compute_frontogenesis(frontgf,frontga,tl,elem,ederiv,hybrid,nets,nete
     use edge_mod, only : edgevpack, edgevunpack
     use bndry_mod, only : bndry_exchangev
     use dyn_comp, only : hvcoord
+    use spmd_utils,      only : iam 
+    use parallel_mod,    only : par 
     implicit none
     type (hybrid_t)      , intent(in) :: hybrid
     type (element_t)     , intent(inout), target :: elem(:)
@@ -150,7 +155,9 @@ subroutine compute_frontogenesis(frontgf,frontga,tl,elem,ederiv,hybrid,nets,nete
        call edgeVpack(edge3, frontgf(:,:,:,ie),nlev,0,ie)
        call edgeVpack(edge3, gradth(:,:,:,:,ie),2*nlev,nlev,ie)
     enddo
-    call bndry_exchangeV(hybrid,edge3)
+    if (iam<par%nprocs) then
+       call bndry_exchangeV(hybrid,edge3)
+    end if
     do ie=nets,nete
        call edgeVunpack(edge3, frontgf(:,:,:,ie),nlev,0,ie)
        call edgeVunpack(edge3, gradth(:,:,:,:,ie),2*nlev,nlev,ie)