printk: Wake up klogd using irq_work
authorFrederic Weisbecker <fweisbec@gmail.com>
Fri, 12 Oct 2012 16:00:23 +0000 (18:00 +0200)
committerFrederic Weisbecker <fweisbec@gmail.com>
Sun, 18 Nov 2012 00:01:49 +0000 (01:01 +0100)
commit74876a98a87a115254b3a66a14b27320b7f0acaa
tree06ed1cff8a92b0c687a7ff2fe31c19e8249bbe3c
parentbc6679aef673f9dcb8f718528fc3df49ff661af9
printk: Wake up klogd using irq_work

klogd is woken up asynchronously from the tick in order
to do it safely.

However if printk is called when the tick is stopped, the reader
won't be woken up until the next interrupt, which might not fire
for a while. As a result, the user may miss some message.

To fix this, lets implement the printk tick using a lazy irq work.
This subsystem takes care of the timer tick state and can
fix up accordingly.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
include/linux/printk.h
init/Kconfig
kernel/printk.c
kernel/time/tick-sched.c
kernel/timer.c