sched/rt: Add Kconfig option to enable panicking for RT throttling

This may be useful for detecting and debugging RT throttling issues. Change-Id: I5807a897d11997d76421c1fcaa2918aad988c6c9 Signed-off-by: Matt Wagantall <[email protected]>
android-legacy · Jul 17, 2014 · bc05334 · bc05334
1 parent 3e43cdd
commit bc05334
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diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
@@ -856,7 +856,16 @@ static void dump_throttled_rt_tasks(struct rt_rq *rt_rq)
 		idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx + 1);
 	}
 out:
+#ifdef CONFIG_PANIC_ON_RT_THROTTLING
+	/*
+	 * Use pr_err() in the BUG() case since printk_sched() will
+	 * not get flushed and deadlock is not a concern.
+	 */
+	pr_err("%s", buf);
+	BUG();
+#else
 	printk_sched("%s", buf);
+#endif
 }
 
 static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
@@ -357,6 +357,15 @@ config SYSRQ_SCHED_DEBUG
 	  "show-blocked-tasks(W)" sysrq-triggers will print additional
 	  scheduling statistics.
 
+config PANIC_ON_RT_THROTTLING
+	bool "Panic on RT throttling"
+	help
+	  Say Y here to enable the kernel to panic when a realtime
+	  runqueue is throttled. This may be useful for detecting
+	  and debugging RT throttling issues.
+
+	  Say N if unsure.
+
 config SCHEDSTATS
 	bool "Collect scheduler statistics"
 	depends on DEBUG_KERNEL && PROC_FS