Commit ab406816 authored by John Ogness's avatar John Ogness Committed by Petr Mladek
Browse files

printk: remove @console_locked 



The static global variable @console_locked is used to help debug
VT code to make sure that certain code paths are running with
the console_lock held. However, this information is also available
with the static global variable @console_kthreads_blocked (for
locking via console_lock()), and the static global variable
@console_kthreads_active (for locking via console_trylock()).

Remove @console_locked and update is_console_locked() to use the
alternative variables.

Signed-off-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220421212250.565456-16-john.ogness@linutronix.de
parent 8e274732

kernel/printk/printk.c

+14 −15
Original line number Diff line number Diff line
@@ -340,15 +340,7 @@ static void console_kthreads_unblock(void) 
	console_kthreads_blocked = false;

}



/*

 * This is used for debugging the mess that is the VT code by

 * keeping track if we have the console semaphore held. It's

 * definitely not the perfect debug tool (we don't know if _WE_

 * hold it and are racing, but it helps tracking those weird code

 * paths in the console code where we end up in places I want

 * locked without the console semaphore held).

 */

static int console_locked, console_suspended;

static int console_suspended;



/*

 *	Array of consoles built from command line options (console=)
@@ -2719,7 +2711,6 @@ void console_lock(void) 
	if (console_suspended)

		return;

	console_kthreads_block();

	console_locked = 1;

	console_may_schedule = 1;

}

EXPORT_SYMBOL(console_lock);
@@ -2744,15 +2735,26 @@ int console_trylock(void) 
		up_console_sem();

		return 0;

	}

	console_locked = 1;

	console_may_schedule = 0;

	return 1;

}

EXPORT_SYMBOL(console_trylock);



/*

 * This is used to help to make sure that certain paths within the VT code are

 * running with the console lock held. It is definitely not the perfect debug

 * tool (it is not known if the VT code is the task holding the console lock),

 * but it helps tracking those weird code paths in the console code such as

 * when the console is suspended: where the console is not locked but no

 * console printing may occur.

 *

 * Note: This returns true when the console is suspended but is not locked.

 *       This is intentional because the VT code must consider that situation

 *       the same as if the console was locked.

 */

int is_console_locked(void)

{

	return (console_locked || atomic_read(&console_kthreads_active));

	return (console_kthreads_blocked || atomic_read(&console_kthreads_active));

}

EXPORT_SYMBOL(is_console_locked);
@@ -2808,8 +2810,6 @@ static inline bool console_is_usable(struct console *con) 


static void __console_unlock(void)

{

	console_locked = 0;



	/*

	 * Depending on whether console_lock() or console_trylock() was used,

	 * appropriately allow the kthread printers to continue.
@@ -3127,7 +3127,6 @@ void console_unblank(void) 
	} else

		console_lock();



	console_locked = 1;

	console_may_schedule = 0;

	for_each_console(c)

		if ((c->flags & CON_ENABLED) && c->unblank)