printk: git rid of [sched_delayed] message for printk_deferred

Commit 458df9fd4815 ("printk: remove separate printk_sched buffers and use
printk buf instead") hardcodes printk_deferred() to KERN_WARNING and
inserts the string "[sched_delayed] " before the actual message.  However
it doesn't take into account the KERN_* prefix of the message, that now
ends up in the middle of the output:

 [sched_delayed] ^a4CE: hpet increased min_delta_ns to 20115 nsec

Fix this by just getting rid of the "[sched_delayed] " scnprintf().  The
prefix is useless since 458df9fd4815 anyway since from that moment
printk_deferred() inserts the message into the kernel printk buffer
immediately.  So if the message eventually gets printed to console, it is
printed in the correct order with other messages and there's no need for
any special prefix.  And if the kernel crashes before the message makes it
to console, then prefix in the printk buffer doesn't make the situation
any better.

Link: http://lkml.org/lkml/2014/9/14/4
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a4436b0cf7698ef209282b1542a8aad2bd6b7c49..e3962d63e3681408f43f90b228b63facc29ba4e7 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1679,12 +1679,7 @@ asmlinkage int vprintk_emit(int facility, int level,
         * The printf needs to come first; we need the syslog
         * prefix which might be passed-in as a parameter.
         */
-       if (in_sched)
-               text_len = scnprintf(text, sizeof(textbuf),
-                                    KERN_WARNING "[sched_delayed] ");
-
-       text_len += vscnprintf(text + text_len,
-                              sizeof(textbuf) - text_len, fmt, args);
+       text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
 
        /* mark and strip a trailing newline */
        if (text_len && text[text_len-1] == '\n') {