--- a/js/src/Makefile.in
+++ b/js/src/Makefile.in
@@ -569,21 +569,21 @@ check-valgrind::
 	$(check-sync-dirs) $(srcdir)/config $(MOZ_SYNC_BUILD_FILES)/config
 	$(check-sync-dirs) $(srcdir)/build $(MOZ_SYNC_BUILD_FILES)/build
 endif
 
 ifdef ENABLE_TRACEJIT
 ifndef WINCE
 check::
 	$(wildcard $(RUN_TEST_PROGRAM)) $(PYTHON) -u $(srcdir)/jit-test/jit_test.py \
-	        --no-slow --no-progress --tinderbox $(DIST)/bin/js$(BIN_SUFFIX)
+	        --no-slow --no-progress --tinderbox --jitflags=m,j,mj,mjp,mjd $(DIST)/bin/js$(BIN_SUFFIX)
 
 check-valgrind::
 	$(wildcard $(RUN_TEST_PROGRAM)) $(PYTHON) -u $(srcdir)/jit-test/jit_test.py \
-	        --valgrind --no-slow --no-progress --tinderbox $(DIST)/bin/js$(BIN_SUFFIX)
+	        --valgrind --no-slow --no-progress --tinderbox --jitflags=m,j,mj,mjp,mjd $(DIST)/bin/js$(BIN_SUFFIX)
 endif
 endif
 
 DIST_GARBAGE = config.cache config.log config.status \
    config/autoconf.mk \
    unallmakefiles js-config js-config.h js-confdefs.h
 
 distclean::

--- a/js/src/jit-test/jit_test.py
+++ b/js/src/jit-test/jit_test.py
@@ -346,18 +346,18 @@ def main(argv):
     op.add_option('-R', '--retest', dest='retest', metavar='FILE',
                   help='Retest using test list file [FILE]')
     op.add_option('-g', '--debug', dest='debug', action='store_true',
                   help='Run test in gdb')
     op.add_option('--valgrind', dest='valgrind', action='store_true',
                   help='Enable the |valgrind| flag, if valgrind is in $PATH.')
     op.add_option('--valgrind-all', dest='valgrind_all', action='store_true',
                   help='Run all tests with valgrind, if valgrind is in $PATH.')
-    op.add_option('--jitflags', dest='jitflags', default='j',
-                  help='Example: --jitflags=j,mj to run each test with -j and -m -j')
+    op.add_option('--jitflags', dest='jitflags', default='mjp',
+                  help='Example: --jitflags=j,mj,mjp to run each test with -j, -m -j, -m -j -p [default=%default]')
     op.add_option('--avoid-stdio', dest='avoid_stdio', action='store_true',
                   help='Use js-shell file indirection instead of piping stdio.')
     op.add_option('--write-failure-output', dest='write_failure_output', action='store_true',
                   help='With --write-failures=FILE, additionally write the output of failed tests to [FILE]')
     (OPTIONS, args) = op.parse_args(argv)
     if len(args) < 1:
         op.error('missing JS_SHELL argument')
     # We need to make sure we are using backslashes on Windows.