kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds

In discussion of how to handle timeouts, it was noted that if
sysctl_hung_task_timeout_seconds is exceeded for a kunit test,
the test task will be killed and an oops generated.  This should
suffice as a means of debugging such timeout issues for now.

Hence remove use of sysctl_hung_task_timeout_secs, which has the
added benefit of avoiding the need to export that symbol from
the core kernel.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 0247a281431a6e9a7b303aaae08472008d1aaeb6..0dd434e40487cf9ef032932369280fc3300520ad 100644 (file)
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c
@@ -11,7 +11,6 @@
 #include <linux/completion.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
-#include <linux/sched/sysctl.h>
 
 #include "try-catch-impl.h"
 
@@ -33,8 +32,6 @@ static int kunit_generic_run_threadfn_adapter(void *data)
 
 static unsigned long kunit_test_timeout(void)
 {
-       unsigned long timeout_msecs;
-
        /*
         * TODO(brendanhiggins@google.com): We should probably have some type of
         * variable timeout here. The only question is what that timeout value
@@ -51,22 +48,11 @@ static unsigned long kunit_test_timeout(void)
         *
         * For more background on this topic, see:
         * https://mike-bland.com/2011/11/01/small-medium-large.html
+        *
+        * If tests timeout due to exceeding sysctl_hung_task_timeout_secs,
+        * the task will be killed and an oops generated.
         */
-       if (sysctl_hung_task_timeout_secs) {
-               /*
-                * If sysctl_hung_task is active, just set the timeout to some
-                * value less than that.
-                *
-                * In regards to the above TODO, if we decide on variable
-                * timeouts, this logic will likely need to change.
-                */
-               timeout_msecs = (sysctl_hung_task_timeout_secs - 1) *
-                               MSEC_PER_SEC;
-       } else {
-               timeout_msecs = 300 * MSEC_PER_SEC; /* 5 min */
-       }
-
-       return timeout_msecs;
+       return 300 * MSEC_PER_SEC; /* 5 min */
 }
 
 void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)