linux-kernel - [PATCH 03/14] printk: add CON

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Date:	Thu,  9 May 2013 16:43:01 -0400
From:	Joern Engel <joern@...fs.org>
To:	linux-kernel@...r.kernel.org
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Jens Axboe <axboe@...nel.dk>, Borislav Petkov <bp@...en8.de>,
	Takashi Iwai <tiwai@...e.de>, Joern Engel <joern@...fs.org>
Subject: [PATCH 03/14] printk: add CON_ALLDATA console flag

For consoles like netconsole and blockconsole the loglevel filtering
really doesn't make any sense.  If a line gets printed at all, please
send it down to that console, no questions asked.

For vga_con, it is a completely different matter, as the user sitting in
front of his console could get spammed by messages while trying to login
or similar.  So ignore_loglevel doesn't work as a one-size-fits-all
approach.  Add a per-console flag instead so that netconsole and
blockconsole can opt-in.

Signed-off-by: Joern Engel <joern@...fs.org>
---
 include/linux/console.h |    1 +
 kernel/printk.c         |    5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/console.h b/include/linux/console.h
index dedb082..eed92ad 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -116,6 +116,7 @@ static inline int con_debug_leave(void)
 #define CON_BOOT	(8)
 #define CON_ANYTIME	(16) /* Safe to call when cpu is offline */
 #define CON_BRL		(32) /* Used for a braille device */
+#define CON_ALLDATA	(64) /* per-console ignore_loglevel */
 
 struct console {
 	char	name[16];
diff --git a/kernel/printk.c b/kernel/printk.c
index 267ce78..5221c59 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1261,8 +1261,6 @@ static void call_console_drivers(int level, const char *text, size_t len)
 
 	trace_console(text, 0, len, len);
 
-	if (level >= console_loglevel && !ignore_loglevel)
-		return;
 	if (!console_drivers)
 		return;
 
@@ -1276,6 +1274,9 @@ static void call_console_drivers(int level, const char *text, size_t len)
 		if (!cpu_online(smp_processor_id()) &&
 		    !(con->flags & CON_ANYTIME))
 			continue;
+		if (level >= console_loglevel && !ignore_loglevel &&
+		    !(con->flags & CON_ALLDATA))
+			continue;
 		con->write(con, text, len);
 	}
 }
-- 
1.7.10.4

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