sched: Use WARN_ONCE for the might_sleep() TASK_RUNNING test

Peter Zijlstra · Ingo Molnar · commit e7097e8bd007 · 2014-11-04T07:17:49.000+01:00
In some cases this can trigger a true flood of output.

Requested-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
@@ -7301,7 +7301,7 @@ void __might_sleep(const char *file, int line, int preempt_offset)
 	 * since we will exit with TASK_RUNNING make sure we enter with it,
 	 * otherwise we will destroy state.
 	 */
-	if (WARN(current->state != TASK_RUNNING,
+	if (WARN_ONCE(current->state != TASK_RUNNING,
 			"do not call blocking ops when !TASK_RUNNING; "
 			"state=%lx set at [<%p>] %pS\n",
 			current->state,
