Merge pull request #3117 from jedwards4b/maint-5.6-merge

Maint 5.6 merge
maint-5.6 branch with merge conflicts resolved

Test suite: scripts_regression_tests.py
Test baseline:
Test namelist changes:
Test status: [bit for bit, roundoff, climate changing]

Fixes

User interface changes?:

Update gh-pages html (Y/N)?:

Code review:

share/util/shr_pio_mod.F90

@@ -686,6 +686,7 @@ subroutine shr_pio_namelist_set(npes,mycomm, pio_stride, pio_root, pio_numiotask
          (pio_iotype .eq. PIO_IOTYPE_PNETCDF .or. &
          pio_iotype .eq. PIO_IOTYPE_NETCDF4P)) then
        pio_numiotasks = 2
+       pio_stride = min(pio_stride, npes/2)
     endif
 
     !--------------------------------------------------------------------------