Revert "printk: Block console kthreads when direct printing will be required"

pmladek · pmladek · commit 05c96b3713aa · 2022-06-23T18:41:40.000+02:00
This reverts commit c323028. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220623145157.21938-3-pmladek@suse.com
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
@@ -3729,9 +3729,7 @@ static bool printer_should_wake(struct console *con, u64 seq)
 		return true;
 
 	if (con->blocked ||
-	    console_kthreads_atomically_blocked() ||
-	    system_state > SYSTEM_RUNNING ||
-	    oops_in_progress) {
+	    console_kthreads_atomically_blocked()) {
 		return false;
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -3729,9 +3729,7 @@ static bool printer_should_wake(struct console *con, u64 seq)`
`3729`	`3729`	`return true;`
`3730`	`3730`
`3731`	`3731`	`if (con->blocked \|\|`
`3732`		`- console_kthreads_atomically_blocked() \|\|`
`3733`		`- system_state > SYSTEM_RUNNING \|\|`
`3734`		`- oops_in_progress) {`
	`3732`	`+ console_kthreads_atomically_blocked()) {`
`3735`	`3733`	`return false;`
`3736`	`3734`	`}`
`3737`	`3735`