ktest: Add BISECT_TRIES to bisect test
For those cases that it takes several tries to hit a bug, it would be
useful for ktest.pl to try a test multiple times before it considers
the test as a pass. To accomplish this, BISECT_TRIES ktest config
option has been added. It is default to one, as most of the time a
bisect only needs to try a test once. But the user can now up this
to make ktest run a given test multiple times. The first failure
that is detected will set a bisect bad. It only repeats on success.
Note, as with all race bugs, there's no guarantee that if it succeeds,
it is really a good bisect. But it helps in case the bug is somewhat
reliable.
You can set BISECT_TRIES to zero, and all tests will be considered
good, unless you also set BISECT_MANUAL.
Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 82006c2..a511d4a 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -41,6 +41,7 @@
"CLEAR_LOG" => 0,
"BISECT_MANUAL" => 0,
"BISECT_SKIP" => 1,
+ "BISECT_TRIES" => 1,
"MIN_CONFIG_TYPE" => "boot",
"SUCCESS_LINE" => "login:",
"DETECT_TRIPLE_FAULT" => 1,
@@ -139,6 +140,7 @@
my $reverse_bisect;
my $bisect_manual;
my $bisect_skip;
+my $bisect_tries;
my $config_bisect_good;
my $bisect_ret_good;
my $bisect_ret_bad;
@@ -276,6 +278,7 @@
"IGNORE_ERRORS" => \$ignore_errors,
"BISECT_MANUAL" => \$bisect_manual,
"BISECT_SKIP" => \$bisect_skip,
+ "BISECT_TRIES" => \$bisect_tries,
"CONFIG_BISECT_GOOD" => \$config_bisect_good,
"BISECT_RET_GOOD" => \$bisect_ret_good,
"BISECT_RET_BAD" => \$bisect_ret_bad,
@@ -2584,12 +2587,29 @@
$buildtype = "useconfig:$minconfig";
}
- my $ret = run_bisect_test $type, $buildtype;
+ # If the user sets bisect_tries to less than 1, then no tries
+ # is a success.
+ my $ret = 1;
- if ($bisect_manual) {
+ # Still let the user manually decide that though.
+ if ($bisect_tries < 1 && $bisect_manual) {
$ret = answer_bisect;
}
+ for (my $i = 0; $i < $bisect_tries; $i++) {
+ if ($bisect_tries > 1) {
+ my $t = $i + 1;
+ doprint("Running bisect trial $t of $bisect_tries:\n");
+ }
+ $ret = run_bisect_test $type, $buildtype;
+
+ if ($bisect_manual) {
+ $ret = answer_bisect;
+ }
+
+ last if (!$ret);
+ }
+
# Are we looking for where it worked, not failed?
if ($reverse_bisect && $ret >= 0) {
$ret = !$ret;