[igt-dev] [PATCH i-g-t] runner: Clean up quickly if the kernel OOPSed during a test

[Chris Wilson]

If the kernel OOPSed during the test, it is unlikely to ever complete.
Furthermore, we have the reason why it won't complete and so do not need
to burden ourselves with the full stacktrace of every process -- or at
least we have a more pressing bug to fix before worrying about the
system deadlock.

v2: Log the post-taint killing.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Petri Latvala <petri.latvala at intel.com>
---
 runner/executor.c | 45 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/runner/executor.c b/runner/executor.c
index f36bfd3dd..71483b749 100644
--- a/runner/executor.c
+++ b/runner/executor.c
@@ -314,13 +314,28 @@ static const struct {
   {(1 << 9), "TAINT_WARN: WARN_ON has happened."},
   {0, 0}};
 
+static unsigned long bad_taints(void)
+{
+	static unsigned long __bad_taints;
+
+	if (!__bad_taints) {
+		for (typeof(*abort_taints) *taint = abort_taints;
+		     taint->bit;
+		     taint++)
+			__bad_taints |= taint->bit;
+	}
+
+	return __bad_taints;
+}
+
+static unsigned long is_tainted(unsigned long taints)
+{
+	return taints & bad_taints();
+}
+
 static unsigned long tainted(unsigned long *taints)
 {
 	FILE *f;
-	unsigned long bad_taints = 0;
-
-	for (typeof(*abort_taints) *taint = abort_taints; taint->bit; taint++)
-		bad_taints |= taint->bit;
 
 	*taints = 0;
 
@@ -330,7 +345,7 @@ static unsigned long tainted(unsigned long *taints)
 		fclose(f);
 	}
 
-	return *taints & bad_taints;
+	return is_tainted(*taints);
 }
 
 static char *handle_taint(void)
@@ -744,17 +759,27 @@ static int monitor_output(pid_t child,
 			return -1;
 		}
 
+		if (tainted(&taints)) /* cancel children after a kernel OOPS */
+			n = 0, intervals_left = 1;
+
 		if (n == 0) {
 			if (--intervals_left)
 				continue;
 
 			switch (killed) {
 			case 0:
-				show_kernel_task_state();
+				if (!is_tainted(taints)) {
+					show_kernel_task_state();
+					if (settings->log_level >= LOG_LEVEL_NORMAL) {
+						outf("Timeout. Killing the current test with SIGQUIT.\n");
 
-				if (settings->log_level >= LOG_LEVEL_NORMAL) {
-					outf("Timeout. Killing the current test with SIGQUIT.\n");
-					fflush(stdout);
+						fflush(stdout);
+					}
+				} else {
+					if (settings->log_level >= LOG_LEVEL_NORMAL) {
+						outf("Killing the test because the kernel is tainted.\n");
+						fflush(stdout);
+					}
 				}
 
 				killed = SIGQUIT;
@@ -791,7 +816,7 @@ static int monitor_output(pid_t child,
 				intervals_left = 1; /* Intervals handled separately for sigkill */
 				break;
 			case SIGKILL:
-				if (!tainted(&taints) && --sigkill_intervals_left) {
+				if (!is_tainted(taints) && --sigkill_intervals_left) {
 					intervals_left = 1;
 					break;
 				}
-- 
2.25.0