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-rw-r--r--kernel/printk.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index a430fd04008b..aee891a869a4 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -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
@@ -982,10 +979,25 @@ 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;
}
/**