1 files changed, 20 insertions, 22 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index b51b1567bb55..6341af77eb65 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -13,7 +13,7 @@
  * Fixed SMP synchronization, 08/08/99, Manfred Spraul
  *     manfred@colorfullife.com
  * Rewrote bits to get rid of console_lock
- *      01Mar01 Andrew Morton <andrewm@uow.edu.au>
+ *      01Mar01 Andrew Morton
  */
 
 #include <linux/kernel.h>
@@ -577,9 +577,6 @@ static int have_callable_console(void)
  * @fmt: format string
  *
  * This is printk().  It can be called from any context.  We want it to work.
- * Be aware of the fact that if oops_in_progress is not set, we might try to
- * wake klogd up which could deadlock on runqueue lock if printk() is called
- * from scheduler code.
  *
  * We try to grab the console_sem.  If we succeed, it's easy - we log the output and
  * call the console drivers.  If we fail to get the semaphore we place the output
@@ -593,6 +590,8 @@ static int have_callable_console(void)
  *
  * See also:
  * printf(3)
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
  */
 
 asmlinkage int printk(const char *fmt, ...)
@@ -982,10 +981,25 @@ int is_console_locked(void)
         return console_locked;
 }
 
-void wake_up_klogd(void)
+static DEFINE_PER_CPU(int, printk_pending);
+
+void printk_tick(void)
 {
-        if (!oops_in_progress && waitqueue_active(&log_wait))
+        if (__get_cpu_var(printk_pending)) {
+                __get_cpu_var(printk_pending) = 0;
                 wake_up_interruptible(&log_wait);
+        }
+}
+
+int printk_needs_cpu(int cpu)
+{
+        return per_cpu(printk_pending, cpu);
+}
+
+void wake_up_klogd(void)
+{
+        if (waitqueue_active(&log_wait))
+                __raw_get_cpu_var(printk_pending) = 1;
 }
 
 /**
@@ -1291,22 +1305,6 @@ static int __init disable_boot_consoles(void)
 }
 late_initcall(disable_boot_consoles);
 
-/**
- * tty_write_message - write a message to a certain tty, not just the console.
- * @tty: the destination tty_struct
- * @msg: the message to write
- *
- * This is used for messages that need to be redirected to a specific tty.
- * We don't put it into the syslog queue right now maybe in the future if
- * really needed.
- */
-void tty_write_message(struct tty_struct *tty, char *msg)
-{
-        if (tty && tty->ops->write)
-                tty->ops->write(tty, msg, strlen(msg));
-        return;
-}
-
 #if defined CONFIG_PRINTK
 
 /*