Merge "printk: Don't take console semaphore in atomic context" (d50ae827) · Commits · e / devices / android_kernel_xiaomi_markw

kernel/printk/printk.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -2065,6 +2065,14 @@ void resume_console(void)
		console_unlock();
		}

		static void __cpuinit console_flush(struct work_struct *work)
		{
		console_lock();
		console_unlock();
		}

		static __cpuinitdata DECLARE_WORK(console_cpu_notify_work, console_flush);

		/**
		* console_cpu_notify - print deferred console messages after CPU hotplug
		* @self: notifier struct
		@@ -2075,6 +2083,9 @@ void resume_console(void)
		* will be spooled but will not show up on the console. This function is
		* called when a new CPU comes online (or fails to come up), and ensures
		* that any such output gets printed.
		*
		* Special handling must be done for cases invoked from an atomic context,
		* as we can't be taking the console semaphore here.
		*/
		static int console_cpu_notify(struct notifier_block *self,
		unsigned long action, void *hcpu)
		@@ -2092,6 +2103,12 @@ static int console_cpu_notify(struct notifier_block *self,
		console_unlock();
		#endif
		break;
		/* invoked with preemption disabled, so defer */
		case CPU_DYING:
		if (!console_trylock())
		schedule_work(&console_cpu_notify_work);
		else
		console_unlock();
		}
		return NOTIFY_OK;
		}