Merge tag 'ktest-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest

Pull config-bisect changes from Steven Rostedt:
 "The big change here is the rewrite of config-bisect.  The old way
  never worked properly as it assumed the bad config was a subset of the
  good config, and just found the config that would break the build.

  The new way does a diff of the bad config verses the good config and
  makes the similar until it finds that one config works and the other
  does not and reports the config that makes that difference.  The two
  configs do not need to be related.  It is much more useful now:

* tag 'ktest-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
  ktest: Update documentation on config_bisect
  ktest: Add the config bisect manual back
  ktest: Remove unused functions
  ktest: Put back in the CONFIG_BISECT_CHECK
  ktest: Rewrite the config-bisect to actually work
  ktest: Some cleanup for improving readability
  ktest: add 2nd parameter of run_command() to set the redirect target file

1 files changed, 270 insertions, 311 deletions

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 40631569a0fd..55ab700f6ba5 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -72,7 +72,7 @@ my %default = (
     "IGNORE_UNUSED"		=> 0,
 );
 
-my $ktest_config;
+my $ktest_config = "ktest.conf";
 my $version;
 my $have_version = 0;
 my $machine;
@@ -149,7 +149,6 @@ my $bisect_ret_abort;
 my $bisect_ret_default;
 my $in_patchcheck = 0;
 my $run_test;
-my $redirect;
 my $buildlog;
 my $testlog;
 my $dmesg;
@@ -522,7 +521,7 @@ sub read_ync {
     return read_prompt 1, $prompt;
 }
 
-sub get_ktest_config {
+sub get_mandatory_config {
     my ($config) = @_;
     my $ans;
 
@@ -553,29 +552,29 @@ sub get_ktest_config {
     }
 }
 
-sub get_ktest_configs {
-    get_ktest_config("MACHINE");
-    get_ktest_config("BUILD_DIR");
-    get_ktest_config("OUTPUT_DIR");
+sub get_mandatory_configs {
+    get_mandatory_config("MACHINE");
+    get_mandatory_config("BUILD_DIR");
+    get_mandatory_config("OUTPUT_DIR");
 
     if ($newconfig) {
-	get_ktest_config("BUILD_OPTIONS");
+	get_mandatory_config("BUILD_OPTIONS");
     }
 
     # options required for other than just building a kernel
     if (!$buildonly) {
-	get_ktest_config("POWER_CYCLE");
-	get_ktest_config("CONSOLE");
+	get_mandatory_config("POWER_CYCLE");
+	get_mandatory_config("CONSOLE");
     }
 
     # options required for install and more
     if ($buildonly != 1) {
-	get_ktest_config("SSH_USER");
-	get_ktest_config("BUILD_TARGET");
-	get_ktest_config("TARGET_IMAGE");
+	get_mandatory_config("SSH_USER");
+	get_mandatory_config("BUILD_TARGET");
+	get_mandatory_config("TARGET_IMAGE");
     }
 
-    get_ktest_config("LOCALVERSION");
+    get_mandatory_config("LOCALVERSION");
 
     return if ($buildonly);
 
@@ -583,7 +582,7 @@ sub get_ktest_configs {
 
     if (!defined($rtype)) {
 	if (!defined($opt{"GRUB_MENU"})) {
-	    get_ktest_config("REBOOT_TYPE");
+	    get_mandatory_config("REBOOT_TYPE");
 	    $rtype = $entered_configs{"REBOOT_TYPE"};
 	} else {
 	    $rtype = "grub";
@@ -591,16 +590,16 @@ sub get_ktest_configs {
     }
 
     if ($rtype eq "grub") {
-	get_ktest_config("GRUB_MENU");
+	get_mandatory_config("GRUB_MENU");
     }
 
     if ($rtype eq "grub2") {
-	get_ktest_config("GRUB_MENU");
-	get_ktest_config("GRUB_FILE");
+	get_mandatory_config("GRUB_MENU");
+	get_mandatory_config("GRUB_FILE");
     }
 
     if ($rtype eq "syslinux") {
-	get_ktest_config("SYSLINUX_LABEL");
+	get_mandatory_config("SYSLINUX_LABEL");
     }
 }
 
@@ -1090,7 +1089,7 @@ sub read_config {
     $test_case = __read_config $config, \$test_num;
 
     # make sure we have all mandatory configs
-    get_ktest_configs;
+    get_mandatory_configs;
 
     # was a test specified?
     if (!$test_case) {
@@ -1529,7 +1528,7 @@ sub fail {
 }
 
 sub run_command {
-    my ($command) = @_;
+    my ($command, $redirect) = @_;
     my $dolog = 0;
     my $dord = 0;
     my $pid;
@@ -2265,9 +2264,7 @@ sub build {
     # Run old config regardless, to enforce min configurations
     make_oldconfig;
 
-    $redirect = "$buildlog";
-    my $build_ret = run_command "$make $build_options";
-    undef $redirect;
+    my $build_ret = run_command "$make $build_options", $buildlog;
 
     if (defined($post_build)) {
 	# Because a post build may change the kernel version
@@ -2360,9 +2357,7 @@ sub child_run_test {
     $poweroff_on_error = 0;
     $die_on_failure = 1;
 
-    $redirect = "$testlog";
-    run_command $run_test or $failed = 1;
-    undef $redirect;
+    run_command $run_test, $testlog or $failed = 1;
 
     exit $failed;
 }
@@ -2789,12 +2784,17 @@ my %dependency;
 sub assign_configs {
     my ($hash, $config) = @_;
 
+    doprint "Reading configs from $config\n";
+
     open (IN, $config)
 	or dodie "Failed to read $config";
 
     while (<IN>) {
+	chomp;
 	if (/^((CONFIG\S*)=.*)/) {
 	    ${$hash}{$2} = $1;
+	} elsif (/^(# (CONFIG\S*) is not set)/) {
+	    ${$hash}{$2} = $1;
 	}
     }
 
@@ -2807,27 +2807,6 @@ sub process_config_ignore {
     assign_configs \%config_ignore, $config;
 }
 
-sub read_current_config {
-    my ($config_ref) = @_;
-
-    %{$config_ref} = ();
-    undef %{$config_ref};
-
-    my @key = keys %{$config_ref};
-    if ($#key >= 0) {
-	print "did not delete!\n";
-	exit;
-    }
-    open (IN, "$output_config");
-
-    while (<IN>) {
-	if (/^(CONFIG\S+)=(.*)/) {
-	    ${$config_ref}{$1} = $2;
-	}
-    }
-    close(IN);
-}
-
 sub get_dependencies {
     my ($config) = @_;
 
@@ -2846,53 +2825,97 @@ sub get_dependencies {
     return @deps;
 }
 
+sub save_config {
+    my ($pc, $file) = @_;
+
+    my %configs = %{$pc};
+
+    doprint "Saving configs into $file\n";
+
+    open(OUT, ">$file") or dodie "Can not write to $file";
+
+    foreach my $config (keys %configs) {
+	print OUT "$configs{$config}\n";
+    }
+    close(OUT);
+}
+
 sub create_config {
-    my @configs = @_;
+    my ($name, $pc) = @_;
 
-    open(OUT, ">$output_config") or dodie "Can not write to $output_config";
+    doprint "Creating old config from $name configs\n";
 
-    foreach my $config (@configs) {
-	print OUT "$config_set{$config}\n";
-	my @deps = get_dependencies $config;
-	foreach my $dep (@deps) {
-	    print OUT "$config_set{$dep}\n";
+    save_config $pc, $output_config;
+
+    make_oldconfig;
+}
+
+# compare two config hashes, and return configs with different vals.
+# It returns B's config values, but you can use A to see what A was.
+sub diff_config_vals {
+    my ($pa, $pb) = @_;
+
+    # crappy Perl way to pass in hashes.
+    my %a = %{$pa};
+    my %b = %{$pb};
+
+    my %ret;
+
+    foreach my $item (keys %a) {
+	if (defined($b{$item}) && $b{$item} ne $a{$item}) {
+	    $ret{$item} = $b{$item};
 	}
     }
 
-    # turn off configs to keep off
-    foreach my $config (keys %config_off) {
-	print OUT "# $config is not set\n";
-    }
+    return %ret;
+}
 
-    # turn off configs that should be off for now
-    foreach my $config (@config_off_tmp) {
-	print OUT "# $config is not set\n";
-    }
+# compare two config hashes and return the configs in B but not A
+sub diff_configs {
+    my ($pa, $pb) = @_;
+
+    my %ret;
+
+    # crappy Perl way to pass in hashes.
+    my %a = %{$pa};
+    my %b = %{$pb};
 
-    foreach my $config (keys %config_ignore) {
-	print OUT "$config_ignore{$config}\n";
+    foreach my $item (keys %b) {
+	if (!defined($a{$item})) {
+	    $ret{$item} = $b{$item};
+	}
     }
-    close(OUT);
 
-    make_oldconfig;
+    return %ret;
 }
 
+# return if two configs are equal or not
+# 0 is equal +1 b has something a does not
+# +1 if a and b have a different item.
+# -1 if a has something b does not
 sub compare_configs {
-    my (%a, %b) = @_;
+    my ($pa, $pb) = @_;
 
-    foreach my $item (keys %a) {
-	if (!defined($b{$item})) {
-	    print "diff $item\n";
+    my %ret;
+
+    # crappy Perl way to pass in hashes.
+    my %a = %{$pa};
+    my %b = %{$pb};
+
+    foreach my $item (keys %b) {
+	if (!defined($a{$item})) {
+	    return 1;
+	}
+	if ($a{$item} ne $b{$item}) {
 	    return 1;
 	}
-	delete $b{$item};
     }
 
-    my @keys = keys %b;
-    if ($#keys) {
-	print "diff2 $keys[0]\n";
+    foreach my $item (keys %a) {
+	if (!defined($b{$item})) {
+	    return -1;
+	}
     }
-    return -1 if ($#keys >= 0);
 
     return 0;
 }
@@ -2900,24 +2923,13 @@ sub compare_configs {
 sub run_config_bisect_test {
     my ($type) = @_;
 
-    return run_bisect_test $type, "oldconfig";
-}
+    my $ret = run_bisect_test $type, "oldconfig";
 
-sub process_passed {
-    my (%configs) = @_;
-
-    doprint "These configs had no failure: (Enabling them for further compiles)\n";
-    # Passed! All these configs are part of a good compile.
-    # Add them to the min options.
-    foreach my $config (keys %configs) {
-	if (defined($config_list{$config})) {
-	    doprint " removing $config\n";
-	    $config_ignore{$config} = $config_list{$config};
-	    delete $config_list{$config};
-	}
+    if ($bisect_manual) {
+	$ret = answer_bisect;
     }
-    doprint "config copied to $outputdir/config_good\n";
-    run_command "cp -f $output_config $outputdir/config_good";
+
+    return $ret;
 }
 
 sub process_failed {
@@ -2928,253 +2940,225 @@ sub process_failed {
     doprint "***************************************\n\n";
 }
 
-sub run_config_bisect {
+# used for config bisecting
+my $good_config;
+my $bad_config;
 
-    my @start_list = keys %config_list;
+sub process_new_config {
+    my ($tc, $nc, $gc, $bc) = @_;
 
-    if ($#start_list < 0) {
-	doprint "No more configs to test!!!\n";
-	return -1;
+    my %tmp_config = %{$tc};
+    my %good_configs = %{$gc};
+    my %bad_configs = %{$bc};
+
+    my %new_configs;
+
+    my $runtest = 1;
+    my $ret;
+
+    create_config "tmp_configs", \%tmp_config;
+    assign_configs \%new_configs, $output_config;
+
+    $ret = compare_configs \%new_configs, \%bad_configs;
+    if (!$ret) {
+	doprint "New config equals bad config, try next test\n";
+	$runtest = 0;
+    }
+
+    if ($runtest) {
+	$ret = compare_configs \%new_configs, \%good_configs;
+	if (!$ret) {
+	    doprint "New config equals good config, try next test\n";
+	    $runtest = 0;
+	}
     }
 
-    doprint "***** RUN TEST ***\n";
+    %{$nc} = %new_configs;
+
+    return $runtest;
+}
+
+sub run_config_bisect {
+    my ($pgood, $pbad) = @_;
+
     my $type = $config_bisect_type;
+
+    my %good_configs = %{$pgood};
+    my %bad_configs = %{$pbad};
+
+    my %diff_configs = diff_config_vals \%good_configs, \%bad_configs;
+    my %b_configs = diff_configs \%good_configs, \%bad_configs;
+    my %g_configs = diff_configs \%bad_configs, \%good_configs;
+
+    my @diff_arr = keys %diff_configs;
+    my $len_diff = $#diff_arr + 1;
+
+    my @b_arr = keys %b_configs;
+    my $len_b = $#b_arr + 1;
+
+    my @g_arr = keys %g_configs;
+    my $len_g = $#g_arr + 1;
+
+    my $runtest = 1;
+    my %new_configs;
     my $ret;
-    my %current_config;
 
-    my $count = $#start_list + 1;
-    doprint "  $count configs to test\n";
+    # First, lets get it down to a single subset.
+    # Is the problem with a difference in values?
+    # Is the problem with a missing config?
+    # Is the problem with a config that breaks things?
 
-    my $half = int($#start_list / 2);
+    # Enable all of one set and see if we get a new bad
+    # or good config.
 
-    do {
-	my @tophalf = @start_list[0 .. $half];
+    # first set the good config to the bad values.
 
-	# keep the bottom half off
-	if ($half < $#start_list) {
-	    @config_off_tmp = @start_list[$half + 1 .. $#start_list];
-	} else {
-	    @config_off_tmp = ();
-	}
+    doprint "d=$len_diff g=$len_g b=$len_b\n";
 
-	create_config @tophalf;
-	read_current_config \%current_config;
-
-	$count = $#tophalf + 1;
-	doprint "Testing $count configs\n";
-	my $found = 0;
-	# make sure we test something
-	foreach my $config (@tophalf) {
-	    if (defined($current_config{$config})) {
-		logit " $config\n";
-		$found = 1;
-	    }
-	}
-	if (!$found) {
-	    # try the other half
-	    doprint "Top half produced no set configs, trying bottom half\n";
-
-	    # keep the top half off
-	    @config_off_tmp = @tophalf;
-	    @tophalf = @start_list[$half + 1 .. $#start_list];
-
-	    create_config @tophalf;
-	    read_current_config \%current_config;
-	    foreach my $config (@tophalf) {
-		if (defined($current_config{$config})) {
-		    logit " $config\n";
-		    $found = 1;
-		}
-	    }
-	    if (!$found) {
-		doprint "Failed: Can't make new config with current configs\n";
-		foreach my $config (@start_list) {
-		    doprint "  CONFIG: $config\n";
-		}
-		return -1;
+    # first lets enable things in bad config that are enabled in good config
+
+    if ($len_diff > 0) {
+	if ($len_b > 0 || $len_g > 0) {
+	    my %tmp_config = %bad_configs;
+
+	    doprint "Set tmp config to be bad config with good config values\n";
+	    foreach my $item (@diff_arr) {
+		$tmp_config{$item} = $good_configs{$item};
 	    }
-	    $count = $#tophalf + 1;
-	    doprint "Testing $count configs\n";
-	}
 
-	$ret = run_config_bisect_test $type;
-	if ($bisect_manual) {
-	    $ret = answer_bisect;
-	}
-	if ($ret) {
-	    process_passed %current_config;
-	    return 0;
+	    $runtest = process_new_config \%tmp_config, \%new_configs,
+			    \%good_configs, \%bad_configs;
 	}
+    }
 
-	doprint "This config had a failure.\n";
-	doprint "Removing these configs that were not set in this config:\n";
-	doprint "config copied to $outputdir/config_bad\n";
-	run_command "cp -f $output_config $outputdir/config_bad";
+    if (!$runtest && $len_diff > 0) {
 
-	# A config exists in this group that was bad.
-	foreach my $config (keys %config_list) {
-	    if (!defined($current_config{$config})) {
-		doprint " removing $config\n";
-		delete $config_list{$config};
-	    }
+	if ($len_diff == 1) {
+	    process_failed $diff_arr[0];
+	    return 1;
 	}
+	my %tmp_config = %bad_configs;
 
-	@start_list = @tophalf;
+	my $half = int($#diff_arr / 2);
+	my @tophalf = @diff_arr[0 .. $half];
 
-	if ($#start_list == 0) {
-	    process_failed $start_list[0];
-	    return 1;
+	doprint "Settings bisect with top half:\n";
+	doprint "Set tmp config to be bad config with some good config values\n";
+	foreach my $item (@tophalf) {
+	    $tmp_config{$item} = $good_configs{$item};
 	}
 
-	# remove half the configs we are looking at and see if
-	# they are good.
-	$half = int($#start_list / 2);
-    } while ($#start_list > 0);
+	$runtest = process_new_config \%tmp_config, \%new_configs,
+			    \%good_configs, \%bad_configs;
 
-    # we found a single config, try it again unless we are running manually
+	if (!$runtest) {
+	    my %tmp_config = %bad_configs;
 
-    if ($bisect_manual) {
-	process_failed $start_list[0];
-	return 1;
-    }
+	    doprint "Try bottom half\n";
 
-    my @tophalf = @start_list[0 .. 0];
+	    my @bottomhalf = @diff_arr[$half+1 .. $#diff_arr];
 
-    $ret = run_config_bisect_test $type;
-    if ($ret) {
-	process_passed %current_config;
+	    foreach my $item (@bottomhalf) {
+		$tmp_config{$item} = $good_configs{$item};
+	    }
+
+	    $runtest = process_new_config \%tmp_config, \%new_configs,
+			    \%good_configs, \%bad_configs;
+	}
+    }
+
+    if ($runtest) {
+	$ret = run_config_bisect_test $type;
+	if ($ret) {
+	    doprint "NEW GOOD CONFIG\n";
+	    %good_configs = %new_configs;
+	    run_command "mv $good_config ${good_config}.last";
+	    save_config \%good_configs, $good_config;
+	    %{$pgood} = %good_configs;
+	} else {
+	    doprint "NEW BAD CONFIG\n";
+	    %bad_configs = %new_configs;
+	    run_command "mv $bad_config ${bad_config}.last";
+	    save_config \%bad_configs, $bad_config;
+	    %{$pbad} = %bad_configs;
+	}
 	return 0;
     }
 
-    process_failed $start_list[0];
-    return 1;
+    fail "Hmm, need to do a mix match?\n";
+    return -1;
 }
 
 sub config_bisect {
     my ($i) = @_;
 
-    my $start_config = $config_bisect;
+    my $type = $config_bisect_type;
+    my $ret;
 
-    my $tmpconfig = "$tmpdir/use_config";
+    $bad_config = $config_bisect;
 
     if (defined($config_bisect_good)) {
-	process_config_ignore $config_bisect_good;
-    }
-
-    # Make the file with the bad config and the min config
-    if (defined($minconfig)) {
-	# read the min config for things to ignore
-	run_command "cp $minconfig $tmpconfig" or
-	    dodie "failed to copy $minconfig to $tmpconfig";
+	$good_config = $config_bisect_good;
+    } elsif (defined($minconfig)) {
+	$good_config = $minconfig;
     } else {
-	unlink $tmpconfig;
-    }
-
-    if (-f $tmpconfig) {
-	load_force_config($tmpconfig);
-	process_config_ignore $tmpconfig;
-    }
-
-    # now process the start config
-    run_command "cp $start_config $output_config" or
-	dodie "failed to copy $start_config to $output_config";
-
-    # read directly what we want to check
-    my %config_check;
-    open (IN, $output_config)
-	or dodie "failed to open $output_config";
-
-    while (<IN>) {
-	if (/^((CONFIG\S*)=.*)/) {
-	    $config_check{$2} = $1;
+	doprint "No config specified, checking if defconfig works";
+	$ret = run_bisect_test $type, "defconfig";
+	if (!$ret) {
+	    fail "Have no good config to compare with, please set CONFIG_BISECT_GOOD";
+	    return 1;
 	}
+	$good_config = $output_config;
     }
-    close(IN);
 
-    # Now run oldconfig with the minconfig
-    make_oldconfig;
+    # we don't want min configs to cause issues here.
+    doprint "Disabling 'MIN_CONFIG' for this test\n";
+    undef $minconfig;
 
-    # check to see what we lost (or gained)
-    open (IN, $output_config)
-	or dodie "Failed to read $start_config";
+    my %good_configs;
+    my %bad_configs;
+    my %tmp_configs;
 
-    my %removed_configs;
-    my %added_configs;
+    doprint "Run good configs through make oldconfig\n";
+    assign_configs \%tmp_configs, $good_config;
+    create_config "$good_config", \%tmp_configs;
+    assign_configs \%good_configs, $output_config;
 
-    while (<IN>) {
-	if (/^((CONFIG\S*)=.*)/) {
-	    # save off all options
-	    $config_set{$2} = $1;
-	    if (defined($config_check{$2})) {
-		if (defined($config_ignore{$2})) {
-		    $removed_configs{$2} = $1;
-		} else {
-		    $config_list{$2} = $1;
-		}
-	    } elsif (!defined($config_ignore{$2})) {
-		$added_configs{$2} = $1;
-		$config_list{$2} = $1;
-	    }
-	} elsif (/^# ((CONFIG\S*).*)/) {
-	    # Keep these configs disabled
-	    $config_set{$2} = $1;
-	    $config_off{$2} = $1;
-	}
-    }
-    close(IN);
+    doprint "Run bad configs through make oldconfig\n";
+    assign_configs \%tmp_configs, $bad_config;
+    create_config "$bad_config", \%tmp_configs;
+    assign_configs \%bad_configs, $output_config;
 
-    my @confs = keys %removed_configs;
-    if ($#confs >= 0) {
-	doprint "Configs overridden by default configs and removed from check:\n";
-	foreach my $config (@confs) {
-	    doprint " $config\n";
-	}
-    }
-    @confs = keys %added_configs;
-    if ($#confs >= 0) {
-	doprint "Configs appearing in make oldconfig and added:\n";
-	foreach my $config (@confs) {
-	    doprint " $config\n";
-	}
-    }
+    $good_config = "$tmpdir/good_config";
+    $bad_config = "$tmpdir/bad_config";
+
+    save_config \%good_configs, $good_config;
+    save_config \%bad_configs, $bad_config;
 
-    my %config_test;
-    my $once = 0;
 
-    @config_off_tmp = ();
+    if (defined($config_bisect_check) && $config_bisect_check ne "0") {
+	if ($config_bisect_check ne "good") {
+	    doprint "Testing bad config\n";
 
-    # Sometimes kconfig does weird things. We must make sure
-    # that the config we autocreate has everything we need
-    # to test, otherwise we may miss testing configs, or
-    # may not be able to create a new config.
-    # Here we create a config with everything set.
-    create_config (keys %config_list);
-    read_current_config \%config_test;
-    foreach my $config (keys %config_list) {
-	if (!defined($config_test{$config})) {
-	    if (!$once) {
-		$once = 1;
-		doprint "Configs not produced by kconfig (will not be checked):\n";
+	    $ret = run_bisect_test $type, "useconfig:$bad_config";
+	    if ($ret) {
+		fail "Bad config succeeded when expected to fail!";
+		return 0;
 	    }
-	    doprint "  $config\n";
-	    delete $config_list{$config};
 	}
-    }
-    my $ret;
+	if ($config_bisect_check ne "bad") {
+	    doprint "Testing good config\n";
 
-    if (defined($config_bisect_check) && $config_bisect_check) {
-	doprint " Checking to make sure bad config with min config fails\n";
-	create_config keys %config_list;
-	$ret = run_config_bisect_test $config_bisect_type;
-	if ($ret) {
-	    doprint " FAILED! Bad config with min config boots fine\n";
-	    return -1;
+	    $ret = run_bisect_test $type, "useconfig:$good_config";
+	    if (!$ret) {
+		fail "Good config failed when expected to succeed!";
+		return 0;
+	    }
 	}
-	doprint " Bad config with min config fails as expected\n";
     }
 
     do {
-	$ret = run_config_bisect;
+	$ret = run_config_bisect \%good_configs, \%bad_configs;
     } while (!$ret);
 
     return $ret if ($ret < 0);
@@ -3455,29 +3439,6 @@ sub read_depends {
     read_kconfig($kconfig);
 }
 
-sub read_config_list {
-    my ($config) = @_;
-
-    open (IN, $config)
-	or dodie "Failed to read $config";
-
-    while (<IN>) {
-	if (/^((CONFIG\S*)=.*)/) {
-	    if (!defined($config_ignore{$2})) {
-		$config_list{$2} = $1;
-	    }
-	}
-    }
-
-    close(IN);
-}
-
-sub read_output_config {
-    my ($config) = @_;
-
-    assign_configs \%config_ignore, $config;
-}
-
 sub make_new_config {
     my @configs = @_;
 
@@ -3863,7 +3824,7 @@ sub make_warnings_file {
     success $i;
 }
 
-$#ARGV < 1 or die "ktest.pl version: $VERSION\n   usage: ktest.pl config-file\n";
+$#ARGV < 1 or die "ktest.pl version: $VERSION\n   usage: ktest.pl [config-file]\n";
 
 if ($#ARGV == 0) {
     $ktest_config = $ARGV[0];
@@ -3873,8 +3834,6 @@ if ($#ARGV == 0) {
 	    exit 0;
 	}
     }
-} else {
-    $ktest_config = "ktest.conf";
 }
 
 if (! -f $ktest_config) {