Merge branch 'rework/suspend-fixes' into for-linus (3a9a3f5f) · Commits · git / linux-net

kernel/printk/internal.h

+5 −3

Original line number	Diff line number	Diff line
		@@ -185,6 +185,8 @@ struct console_flush_type {
		bool legacy_offload;
		};

		extern bool console_irqwork_blocked;

		/*
		* Identify which console flushing methods should be used in the context of
		* the caller.
		@@ -196,7 +198,7 @@ static inline void printk_get_console_flush_type(struct console_flush_type *ft)
		switch (nbcon_get_default_prio()) {
		case NBCON_PRIO_NORMAL:
		if (have_nbcon_console && !have_boot_console) {
		if (printk_kthreads_running)
		if (printk_kthreads_running && !console_irqwork_blocked)
		ft->nbcon_offload = true;
		else
		ft->nbcon_atomic = true;
		@@ -206,7 +208,7 @@ static inline void printk_get_console_flush_type(struct console_flush_type *ft)
		if (have_legacy_console \|\| have_boot_console) {
		if (!is_printk_legacy_deferred())
		ft->legacy_direct = true;
		else
		else if (!console_irqwork_blocked)
		ft->legacy_offload = true;
		}
		break;
		@@ -219,7 +221,7 @@ static inline void printk_get_console_flush_type(struct console_flush_type *ft)
		if (have_legacy_console \|\| have_boot_console) {
		if (!is_printk_legacy_deferred())
		ft->legacy_direct = true;
		else
		else if (!console_irqwork_blocked)
		ft->legacy_offload = true;
		}
		break;

kernel/printk/nbcon.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -1302,6 +1302,13 @@ void nbcon_kthreads_wake(void)
		if (!printk_kthreads_running)
		return;

		/*
		* It is not allowed to call this function when console irq_work
		* is blocked.
		*/
		if (WARN_ON_ONCE(console_irqwork_blocked))
		return;

		cookie = console_srcu_read_lock();
		for_each_console_srcu(con) {
		if (!(console_srcu_read_flags(con) & CON_NBCON))
		@@ -1892,7 +1899,7 @@ void nbcon_device_release(struct console *con)
		if (console_trylock())
		console_unlock();
		} else if (ft.legacy_offload) {
		printk_trigger_flush();
		defer_console_output();
		}
		}
		console_srcu_read_unlock(cookie);

kernel/printk/printk.c

+66 −17

Original line number	Diff line number	Diff line
		@@ -462,6 +462,9 @@ bool have_boot_console;
		/* See printk_legacy_allow_panic_sync() for details. */
		bool legacy_allow_panic_sync;

		/* Avoid using irq_work when suspending. */
		bool console_irqwork_blocked;

		#ifdef CONFIG_PRINTK
		DECLARE_WAIT_QUEUE_HEAD(log_wait);
		static DECLARE_WAIT_QUEUE_HEAD(legacy_wait);
		@@ -2390,7 +2393,7 @@ asmlinkage int vprintk_emit(int facility, int level,
		/* If called from the scheduler, we can not call up(). */
		if (level == LOGLEVEL_SCHED) {
		level = LOGLEVEL_DEFAULT;
		ft.legacy_offload \|= ft.legacy_direct;
		ft.legacy_offload \|= ft.legacy_direct && !console_irqwork_blocked;
		ft.legacy_direct = false;
		}

		@@ -2426,7 +2429,7 @@ asmlinkage int vprintk_emit(int facility, int level,

		if (ft.legacy_offload)
		defer_console_output();
		else
		else if (!console_irqwork_blocked)
		wake_up_klogd();

		return printed_len;
		@@ -2730,10 +2733,20 @@ void console_suspend_all(void)
		{
		struct console *con;

		if (!console_suspend_enabled)
		return;
		if (console_suspend_enabled)
		pr_info("Suspending console(s) (use no_console_suspend to debug)\n");

		/*
		* Flush any console backlog and then avoid queueing irq_work until
		* console_resume_all(). Until then deferred printing is no longer
		* triggered, NBCON consoles transition to atomic flushing, and
		* any klogd waiters are not triggered.
		*/
		pr_flush(1000, true);
		console_irqwork_blocked = true;

		if (!console_suspend_enabled)
		return;

		console_list_lock();
		for_each_console(con)
		@@ -2754,9 +2767,14 @@ void console_resume_all(void)
		struct console_flush_type ft;
		struct console *con;

		if (!console_suspend_enabled)
		return;
		/*
		* Allow queueing irq_work. After restoring console state, deferred
		* printing and any klogd waiters need to be triggered in case there
		* is now a console backlog.
		*/
		console_irqwork_blocked = false;

		if (console_suspend_enabled) {
		console_list_lock();
		for_each_console(con)
		console_srcu_write_flags(con, con->flags & ~CON_SUSPENDED);
		@@ -2768,12 +2786,15 @@ void console_resume_all(void)
		* that they are guaranteed to wake up and resume printing.
		*/
		synchronize_srcu(&console_srcu);
		}

		printk_get_console_flush_type(&ft);
		if (ft.nbcon_offload)
		nbcon_kthreads_wake();
		if (ft.legacy_offload)
		defer_console_output();
		else
		wake_up_klogd();

		pr_flush(1000, true);
		}
		@@ -4559,6 +4580,13 @@ static void __wake_up_klogd(int val)
		if (!printk_percpu_data_ready())
		return;

		/*
		* It is not allowed to call this function when console irq_work
		* is blocked.
		*/
		if (WARN_ON_ONCE(console_irqwork_blocked))
		return;

		preempt_disable();
		/*
		* Guarantee any new records can be seen by tasks preparing to wait
		@@ -4615,8 +4643,29 @@ void defer_console_output(void)
		__wake_up_klogd(PRINTK_PENDING_WAKEUP \| PRINTK_PENDING_OUTPUT);
		}

		/**
		* printk_trigger_flush - Attempt to flush printk buffer to consoles.
		*
		* If possible, flush the printk buffer to all consoles in the caller's
		* context. If offloading is available, trigger deferred printing.
		*
		* This is best effort. Depending on the system state, console states,
		* and caller context, no actual flushing may result from this call.
		*/
		void printk_trigger_flush(void)
		{
		struct console_flush_type ft;

		printk_get_console_flush_type(&ft);
		if (ft.nbcon_atomic)
		nbcon_atomic_flush_pending();
		if (ft.nbcon_offload)
		nbcon_kthreads_wake();
		if (ft.legacy_direct) {
		if (console_trylock())
		console_unlock();
		}
		if (ft.legacy_offload)
		defer_console_output();
		}