From: David Wells <drwells@email.unc.edu>
Date: Thu, 19 May 2022 13:53:29 +0000 (-0400)
Subject: Don't set ghost values in diagonal matrices.
X-Git-Tag: v9.4.0-rc1~198^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F12664%2Fhead;p=dealii.git

Don't set ghost values in diagonal matrices.

We never read them.
---

diff --git a/doc/news/changes/incompatibilities/20210817DavidWells b/doc/news/changes/incompatibilities/20210817DavidWells
new file mode 100644
index 0000000000..aae77d62b1
--- /dev/null
+++ b/doc/news/changes/incompatibilities/20210817DavidWells
@@ -0,0 +1,4 @@
+Changed: The DiagonalMatrix objects set up by MatrixFreeOperators::Base and
+its inheriting classes no set ghost entries.
+<br>
+(David Wells, 2021/08/17)
diff --git a/include/deal.II/matrix_free/operators.h b/include/deal.II/matrix_free/operators.h
index f0843f42a6..44f8bfaede 100644
--- a/include/deal.II/matrix_free/operators.h
+++ b/include/deal.II/matrix_free/operators.h
@@ -1909,8 +1909,7 @@ namespace MatrixFreeOperators
           1. / inverse_diagonal_vector.local_element(i);
       }
 
-    inverse_diagonal_vector.update_ghost_values();
-    diagonal_vector.update_ghost_values();
+    // We never need ghost values so don't update them
   }
 
 
@@ -2206,8 +2205,7 @@ namespace MatrixFreeOperators
       else
         inverse_diagonal_vector.local_element(i) = 1.;
 
-    inverse_diagonal_vector.update_ghost_values();
-    diagonal_vector.update_ghost_values();
+    // We never need ghost values so don't update them
   }