--- valgrind/gdbserver_tests/mcinvokeWS.vgtest	(revision 12990)
+++ valgrind/gdbserver_tests/mcinvokeWS.vgtest	(working copy)
@@ -4,7 +4,8 @@
 args: 1 10000000 0 -S-S-S-S
 vgopts: --tool=memcheck --vgdb=yes --vgdb-prefix=./vgdb-prefix-mcinvokeWS
 stderr_filter: filter_make_empty
-prereq: test -f vgdb.ptraceinvoker
+# One some ppc64 installs this test just hangs
+prereq: test -f vgdb.ptraceinvoker && ! `../tests/arch_test ppc64`
 progB: invoker
 argsB: 10 --vgdb-prefix=./vgdb-prefix-mcinvokeWS --wait=60 -c v.wait 0
 # if the --wait is not enough, the test will fail or block
Index: gdbserver_tests/mcinvokeRU.vgtest
===================================================================
--- valgrind/gdbserver_tests/mcinvokeRU.vgtest	(revision 12990)
+++ valgrind/gdbserver_tests/mcinvokeRU.vgtest	(working copy)
@@ -7,6 +7,8 @@
 # as the Valgrind process is always busy, we do not need the vgdb.ptraceinvoker prereq.
 # We even disable ptrace invoker to avoid spurious attach error message
 # on kernels where ptrace is restricted.
+# One some ppc64 installs this test just hangs
+prereq: ! `../tests/arch_test ppc64`
 progB: invoker
 argsB: 10 --vgdb-prefix=./vgdb-prefix-mcinvokeRU --max-invoke-ms=0 --wait=60 -c v.wait 0
 # if the --wait is not enough, the test will fail or block.