Merge remote-tracking branch 'ktest/for-next'

2 files changed, 297 insertions, 349 deletions

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 40631569a0f..55ab700f6ba 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) {
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index 172eec4517f..911e45ad657 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -1098,49 +1098,35 @@
 #
 #  The way it works is this:
 #
-#   First it finds a config to work with. Since a different version, or
-#   MIN_CONFIG may cause different dependecies, it must run through this
-#   preparation.
+#   You can specify a good config with CONFIG_BISECT_GOOD, otherwise it
+#   will use the MIN_CONFIG, and if that's not specified, it will use
+#   the config that comes with "make defconfig".
 #
-#   Overwrites any config set in the bad config with a config set in
-#   either the MIN_CONFIG or ADD_CONFIG. Thus, make sure these configs
-#   are minimal and do not disable configs you want to test:
-#   (ie.  # CONFIG_FOO is not set).
+#   It runs both the good and bad configs through a make oldconfig to
+#   make sure that they are set up for the kernel that is checked out.
 #
-#   An oldconfig is run on the bad config and any new config that
-#   appears will be added to the configs to test.
+#   It then reads the configs that are set, as well as the ones that are
+#   not set for both the good and bad configs, and then compares them.
+#   It will set half of the good configs within the bad config (note,
+#   "set" means to make the bad config match the good config, a config
+#   in the good config that is off, will be turned off in the bad
+#   config. That is considered a "set").
 #
-#   Finally, it generates a config with the above result and runs it
-#   again through make oldconfig to produce a config that should be
-#   satisfied by kconfig.
+#   It tests this new config and if it works, it becomes the new good
+#   config, otherwise it becomes the new bad config. It continues this
+#   process until there's only one config left and it will report that
+#   config.
 #
-#   Then it starts the bisect.
+#   The "bad config" can also be a config that is needed to boot but was
+#   disabled because it depended on something that wasn't set.
 #
-#   The configs to test are cut in half. If all the configs in this
-#   half depend on a config in the other half, then the other half
-#   is tested instead. If no configs are enabled by either half, then
-#   this means a circular dependency exists and the test fails.
+#   During this process, it saves the current good and bad configs in
+#   ${TMP_DIR}/good_config and ${TMP_DIR}/bad_config respectively.
+#   If you stop the test, you can copy them to a new location to
+#   reuse them again.
 #
-#   A config is created with the test half, and the bisect test is run.
-#
-#   If the bisect succeeds, then all configs in the generated config
-#   are removed from the configs to test and added to the configs that
-#   will be enabled for all builds (they will be enabled, but not be part
-#   of the configs to examine).
-#
-#   If the bisect fails, then all test configs that were not enabled by
-#   the config file are removed from the test. These configs will not
-#   be enabled in future tests. Since current config failed, we consider
-#   this to be a subset of the config that we started with.
-#
-#   When we are down to one config, it is considered the bad config.
-#
-#   Note, the config chosen may not be the true bad config. Due to
-#   dependencies and selections of the kbuild system, mulitple
-#   configs may be needed to cause a failure. If you disable the
-#   config that was found and restart the test, if the test fails
-#   again, it is recommended to rerun the config_bisect with a new
-#   bad config without the found config enabled.
+#   Although the MIN_CONFIG may be the config it starts with, the
+#   MIN_CONFIG is ignored.
 #
 #  The option BUILD_TYPE will be ignored.
 #
@@ -1160,13 +1146,16 @@
 # CONFIG_BISECT_GOOD (optional)
 #  If you have a good config to start with, then you
 #  can specify it with CONFIG_BISECT_GOOD. Otherwise
-#  the MIN_CONFIG is the base.
+#  the MIN_CONFIG is the base, if MIN_CONFIG is not set
+#  It will build a config with "make defconfig"
 #
 # CONFIG_BISECT_CHECK (optional)
 #  Set this to 1 if you want to confirm that the config ktest
 #  generates (the bad config with the min config) is still bad.
 #  It may be that the min config fixes what broke the bad config
 #  and the test will not return a result.
+#  Set it to "good" to test only the good config and set it
+#  to "bad" to only test the bad config.
 #
 # Example:
 #   TEST_START