[PATCH 3/9] printk: add CON_ALLDATA console flag

Joern Engel
2013-02-28T23:04:39Z

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@logfs.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