Merge "printk: Make the console flush configurable in hotplug path" (da66836d) · Commits · e / devices / android_kernel_oneplus_sm8150

init/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -531,6 +531,16 @@ config LOG_BUF_SHIFT
		13 => 8 KB
		12 => 4 KB

		config CONSOLE_FLUSH_ON_HOTPLUG
		bool "Enable console flush configurable in hot plug code path"
		depends on HOTPLUG_CPU
		def_bool n
		help
		In cpu hot plug path console lock acquire and release causes the
		console to flush. If console lock is not free hot plug latency
		increases. So make console flush configurable in hot plug path
		and default disabled to help in cpu hot plug latencies.

		config LOG_CPU_MAX_BUF_SHIFT
		int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
		depends on SMP

+8 −2

Original line number	Diff line number	Diff line
		@@ -2021,6 +2021,8 @@ void resume_console(void)
		console_unlock();
		}

		#ifdef CONFIG_CONSOLE_FLUSH_ON_HOTPLUG

		/**
		* console_cpu_notify - print deferred console messages after CPU hotplug
		* @cpu: unused
		@@ -2040,6 +2042,8 @@ static int console_cpu_notify(unsigned int cpu)
		return 0;
		}

		#endif

		/**
		* console_lock - lock the console system for exclusive use.
		*
		@@ -2652,7 +2656,7 @@ void __init console_init(void)
		static int __init printk_late_init(void)
		{
		struct console *con;
		int ret;
		int ret = 0;

		for_each_console(con) {
		if (!(con->flags & CON_BOOT))
		@@ -2674,13 +2678,15 @@ static int __init printk_late_init(void)
		unregister_console(con);
		}
		}
		#ifdef CONFIG_CONSOLE_FLUSH_ON_HOTPLUG
		ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL,
		console_cpu_notify);
		WARN_ON(ret < 0);
		ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
		console_cpu_notify, NULL);
		WARN_ON(ret < 0);
		return 0;
		#endif
		return ret;
		}
		late_initcall(printk_late_init);