On 2025-02-05, "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: >> If there is no backlog, pr_flush() returns immediately. > > OK, so I don't need to add "if (IS_ENABLED(CONFIG_PREEMPT_RT))" to guard > it, then? For !CONFIG_PREEMPT_RT, if there are legacy consoles registered, pr_flush() will additionally perform a blocking lock on the console_lock. The kernel is in a clean shutdown path, so it should not be a risk to block on the console_lock. But the console_lock is one of the ugly global locks (semaphore, actually) we are working to remove because sometimes it still causes problems. @pmladek: What do you think? Should we have a CONFIG_PREEMPT_RT guard, which would always be safe? Or do you feel comfortable performing a console_lock() in the shutdown path for !CONFIG_PREEMPT_RT? John
