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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)
577 * @fmt: format string 577 * @fmt: format string
578 * 578 *
579 * This is printk(). It can be called from any context. We want it to work. 579 * This is printk(). It can be called from any context. We want it to work.
580 * Be aware of the fact that if oops_in_progress is not set, we might try to
581 * wake klogd up which could deadlock on runqueue lock if printk() is called
582 * from scheduler code.
583 * 580 *
584 * We try to grab the console_sem. If we succeed, it's easy - we log the output and 581 * We try to grab the console_sem. If we succeed, it's easy - we log the output and
585 * call the console drivers. If we fail to get the semaphore we place the output 582 * call the console drivers. If we fail to get the semaphore we place the output
@@ -982,10 +979,25 @@ int is_console_locked(void)
982 return console_locked; 979 return console_locked;
983} 980}
984 981
985void wake_up_klogd(void) 982static DEFINE_PER_CPU(int, printk_pending);
983
984void printk_tick(void)
986{ 985{
987 if (!oops_in_progress && waitqueue_active(&log_wait)) 986 if (__get_cpu_var(printk_pending)) {
987 __get_cpu_var(printk_pending) = 0;
988 wake_up_interruptible(&log_wait); 988 wake_up_interruptible(&log_wait);
989 }
990}
991
992int printk_needs_cpu(int cpu)
993{
994 return per_cpu(printk_pending, cpu);
995}
996
997void wake_up_klogd(void)
998{
999 if (waitqueue_active(&log_wait))
1000 __raw_get_cpu_var(printk_pending) = 1;
989} 1001}
990 1002
991/** 1003/**