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-rw-r--r--kernel/trace/ring_buffer.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bd1c35a4fbcc..d9c8bcafb120 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5,7 +5,6 @@
*/
#include <linux/ring_buffer.h>
#include <linux/trace_clock.h>
-#include <linux/ftrace_irq.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
@@ -669,7 +668,7 @@ static struct list_head *rb_list_head(struct list_head *list)
* the reader page). But if the next page is a header page,
* its flags will be non zero.
*/
-static int inline
+static inline int
rb_is_head_page(struct ring_buffer_per_cpu *cpu_buffer,
struct buffer_page *page, struct list_head *list)
{
@@ -1429,6 +1428,17 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
}
EXPORT_SYMBOL_GPL(ring_buffer_resize);
+void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
+{
+ mutex_lock(&buffer->mutex);
+ if (val)
+ buffer->flags |= RB_FL_OVERWRITE;
+ else
+ buffer->flags &= ~RB_FL_OVERWRITE;
+ mutex_unlock(&buffer->mutex);
+}
+EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
+
static inline void *
__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
{
@@ -2162,11 +2172,19 @@ rb_reserve_next_event(struct ring_buffer *buffer,
if (likely(ts >= cpu_buffer->write_stamp)) {
delta = diff;
if (unlikely(test_time_stamp(delta))) {
+ int local_clock_stable = 1;
+#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+ local_clock_stable = sched_clock_stable;
+#endif
WARN_ONCE(delta > (1ULL << 59),
- KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n",
+ KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
(unsigned long long)delta,
(unsigned long long)ts,
- (unsigned long long)cpu_buffer->write_stamp);
+ (unsigned long long)cpu_buffer->write_stamp,
+ local_clock_stable ? "" :
+ "If you just came from a suspend/resume,\n"
+ "please switch to the trace global clock:\n"
+ " echo global > /sys/kernel/debug/tracing/trace_clock\n");
add_timestamp = 1;
}
}