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-rw-r--r--kernel/printk.c67
1 files changed, 21 insertions, 46 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index a430fd04008..e651ab05655 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>
@@ -233,45 +233,6 @@ static inline void boot_delay_msec(void)
#endif
/*
- * Return the number of unread characters in the log buffer.
- */
-static int log_buf_get_len(void)
-{
- return logged_chars;
-}
-
-/*
- * Copy a range of characters from the log buffer.
- */
-int log_buf_copy(char *dest, int idx, int len)
-{
- int ret, max;
- bool took_lock = false;
-
- if (!oops_in_progress) {
- spin_lock_irq(&logbuf_lock);
- took_lock = true;
- }
-
- max = log_buf_get_len();
- if (idx < 0 || idx >= max) {
- ret = -1;
- } else {
- if (len > max)
- len = max;
- ret = len;
- idx += (log_end - max);
- while (len-- > 0)
- dest[len] = LOG_BUF(idx + len);
- }
-
- if (took_lock)
- spin_unlock_irq(&logbuf_lock);
-
- return ret;
-}
-
-/*
* Commands to do_syslog:
*
* 0 -- Close the log. Currently a NOP.
@@ -577,9 +538,6 @@ 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 +551,8 @@ 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, ...)
@@ -702,7 +662,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
if (recursion_bug) {
recursion_bug = 0;
strcpy(printk_buf, recursion_bug_msg);
- printed_len = sizeof(recursion_bug_msg);
+ printed_len = strlen(recursion_bug_msg);
}
/* Emit the output into the temporary buffer */
printed_len += vscnprintf(printk_buf + printed_len,
@@ -982,10 +942,25 @@ 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;
}
/**